Testosterone implants releasing about 0\m=.\2 mg./day had no effect on sebum production in hypophysectomized-castrated rats, even though treatment by a similar dose of testosterone has been shown to effect a marked increase in sebaceous activity in rats with intact pituitaries.A preparation of porcine growth hormone, and a preparation of prolactin (luteotrophin) which had no growth hormone activity, were each capable of fully restoring the response of the sebaceous gland in hypophysectomized male rats to testosterone, though the pituitary hormones had no effect by themselves. The stimulation of sebaceous activity was measured both by the increase in sebum production and by the increased incidence of cell division in the sebaceous glands.The responses of the preputial glands and seminal vesicles to testosterone were independent of the presence of the pituitary, and were not significantly enhanced by the hypophysial hormones.
After declining by over 80% in the last 30 yr, Steller sea lion Eumetopias jubatus (SSL) populations in Alaska remain low with no sign of recovery. To better examine the potential effects of nutritional stress, foraging studies are needed. Currently available biotelemetry techniques are either incapable of precisely quantifying prey captures or have not been validated for SSLs. Our objectives were to (1) determine whether SSL fish-capture attempts (FCAs) produce a head surge acceleration signal; (2) determine whether acceleration of the head relative to the body (differential) produces a more distinct signal than head acceleration alone (dynamic); and (3) develop a method for predicting FCAs using accelerometry. We attached accelerometers to the head and torso of 2 captive SSLs at the Alaska SeaLife Center and allowed them to feed on live fish. For the first SSL, we used video to classify FCAs during foraging trials and modeled the association between FCAs and parameters created using both dynamic and differential acceleration. Model coefficients were used to predict FCAs for a second SSL, and the results were compared with video. Head acceleration spikes were found in all FCAs. The dynamic model performed slightly better than the differential model at correctly predicting FCAs. Although the model did not perform exceptionally at identifying individual FCAs, it did predict at least 1 FCA in 96% of fish-chasing events and made only 1 false FCA prediction during 392 min of non-foraging. This study demonstrates that head accelerometry is useful for estimating SSL foraging effort.
Electronic telemetry devices have enabled many novel and important data collection and experimental opportunities for difficult to observe species. Externally attached devices have limited retention and may affect thermoregulation, energetics, social and reproductive behavior, visibility, predation risk and entanglement. Internally placed, surgically implanted devices can mitigate some of these effects and may open additional experimental opportunities. However, improper implementation can significantly affect animals and data. From a review of recent studies using fully implanted tags and studying their effects, we present 15 specific best practice recommendations for the use of such tags in pinnipeds. Recommendations address issues including device size, coating and sterilization, implantation surgery and effect assessment, within the framework of the Three R's: Reduction, Refinement, Replacement. While developed for pinnipeds, these recommendations could apply to other aquatic mammals and vertebrates and to partially implanted or even external tags.
SUMMARY
The quantitative changes in body hair growth, and sebaceous secretion, as well as plasma sex hormone binding globulin, luteinizing hormone and follicle stimulating hormone, testosterone and androstenedione were measured in a hirsute woman aged 21 years under ‘reverse sequential’ treatment with cyproterone acetate and ethinyl oestradiol. The subject, before treatment, had normal excretion of 17‐oxosteroids, 17‐oxogenic steroids, androsterone, dehydroepiandrosterone and aetiocholanolone.
The rate of hair growth on the thigh and the average diameter of the hairs was significantly reduced after only 2 cycles of treatment. After 6–7 cycles the length attained by the terminal hairs was reduced and this appeared to be due mainly to change in growth rate rather than to alteration in the duration of anagen.
The shorter and thinner hairs also had a much shorter region of pigniented medulla. A progressive decrease in the extent and continuity of the medulla could be detected after 3 cycles of treatment.
Sebaceous secretion was also reduced after 2 cycles of treatment; and there was thereafter steady improvement of the pustular acne.
Sex hormone binding globulin levels were low before treatment, unaltered by a first cycle of cyproterone acetate alone, but increased by addition of ethinyl oestradiol. Gonadotrophins remained low throughout, while testosterone and androstenedione levels, initially high, were substantially suppressed.
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