Relationship of ovarian and thyroid function

In an investigation of relationships between ovarian function and thyroid function, three groups of ten women each were studied by means of radioactive iodine uptake. In the first group no significant changes were noted during normal menstrual cycles. The second group, women who had dysfunctional uterine bleeding and were under treatment with diethylstilbestrol, most of the patients had no significant change in the uptake of radioactive iodine. Three patients did show a small increase in the uptake. (A fourth patient had a very bizarre result with a very great increase in the uptake, but it is felt that some undetected error was involved.)The third group was made up of women without evident ovarian function. Under treatment with diethylstilbestrol one patient showed a small increase in iodine uptake. The other nine had no significant change. No convincing evidence was found of any change in thyroid function as measured by the uptake of radioactive iodine-either during normal menstrual cycles or following the administration of diethylstilbestrol in dosages of 3 mg. daily for two to three weeks.     

Immunofluorescent Visualization of 100 Å Filaments in Different Cultured Chick Embryo Cell Types

Antibody prepared against the 55,000 dalton subunit of reconstituted chick gizzard 100 A filaments (anti-G55K) bound to the 100 Å filaments of chick smooth muscle, cardiac muscle, and skeletal muscle cells, and to the 100 Å filaments of Schwann cells and satellite glial cells of the peripheral nervous system. Anti-G55K did not bind to replicating presumptive myoblasts, fibroblasts, chondroblasts, pigment cells, neurons, or to central nervous system glial cells. This contrasted with the wider range of binding of antibody to the 58,000 dalton subunit of chick fibroblast 100 A filaments (anti-F58K) which bound to the 100 Å filaments of all cell types examined except hepatocytes and skin epithelial cells. Anti-G55K staining revealed a morphologically distinct distribution of 100 A filaments in the three types of muscle cells. Spindle shaped smooth muscle cells exhibited dense fluorescent staining near the poles of the cells, and also exhibited unique patches of fluorescent material after cytochalasin B and Colcemid treatment. In myotubes, the fluorescence was limited to longitudinal bundles of filaments between the striated myofibrils. Cardiac cells contained uniformly distributed fine filaments. Lastly, smooth muscle cells in various phases of mitosis bound the anti-G55K, whereas replicating presumptive skeletal myoblasts failed to bind the anti-G55K.     

Trophic structure of a boreal forest arthropod community revealed by stable isotope (δ13C, δ15N) analyses

Terrestrial arthropods are important components of boreal ecosystems but relatively little is known about their trophic structure within communities. We measured δ¹³C and δ¹⁵N values in a broad range of arthropod taxa (Coleoptera, Diptera, Ephemeroptera, Homoptera, Hymenoptera, Lepidoptera, Odonata, Orthoptera, Araneae) from boreal forest in Prince Albert National Park, Saskatchewan, Canada. Isotopic measurements supported previous conventional investigations on foraging niches based on stomach content analysis and direct feeding observations but additional, new information was also obtained using the stable isotope approach. Significant differences were observed in both δ¹⁵N and δ¹³C values between various orders and families or superfamilies within orders. Higher variance in stable isotope values for scavengers (e.g. carrion beetles; Coleoptera, Silphidae) and generalists (e.g. ground beetles; Coleoptera, Carabidae) was found compared to specialists (e.g. grasshoppers; Orthoptera). Consistent isotopic differences between terrestrial and aquatic species were not found. However, aquatic insect δ¹³C values tended to be lower than those of their terrestrial counterparts. We discuss the potential for using stable isotope methods to reconstruct trophic linkages and interaction involving arthropods.