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Biomedical subjects

K B Reilly

Publications and source records attributed to K B Reilly.

8 recordsLinked to original sources
PubMed1983

Circadian rhythms in house sparrows: lighting ad lib.

House sparrows, Passer domesticus, have circadian rhythms of locomotor activity that can be entrained by light-dark cycles. Perch-hopping activity was studied in house sparrows that were given control of their own lighting. In one series of experiments, sparrows permitted to select their own lighting most commonly chose circadian freerunning cycles. The period of the selected freerunning cycles was 23.2 hr (0.9 hr shorter than the period length the sparrows exhibited in constant dark). The average self-imposed "photoperiods" in the selected freerunning cycles ranged from 8.2-10.0 hr. In a second series of experiments, sparrows were exposed to LDLD1:6:1:16. This cycle can be interpreted ambiguously as the skeleton of a short photoperiod, LD8:16, or of a long photoperiod, LD18:6. All the birds (13 birds; 23 trials) interpreted the skeleton cycle as a short photoperiod because they entrained to it as they would to LD8:16.

Animals↗
PubMed1982

Ultrasonic measurement of the femur length as an index of fetal gestational age.

Fetal femur length was measured with a linear-array, real-time ultrasound scanner in 145 uncomplicated gravid patients from 16 to 42 weeks' gestation. The data were analyzed by means of the method of least-squares linear regression. The results of this analysis generated the following equation: Y = -0.6809 + 0.2127 X (Y = femur length; X = gestational age.) With the use of these data, the error in estimation of gestational age given femur length in the interval 25 to 35 weeks' gestation is less than 5 days. Outside these intervals, there is less precision in this measurement, with a range from 8 days at 15 weeks to 6 days at 40 weeks. Furthermore, the correlation coefficient of gestational age versus fetal femur length is statistically greater than that of the gestational age versus fetal biparietal diameter. These results suggest that the measurement of the fetal femur length is a more precise index of gestational age than is the biparietal diameter. We propose that the ultrasonic measurement of the fetal femur length is a sensitive and precise variable for estimation of fetal growth and development.

Female↗
PubMed1978

The pineal gland: a biological clock in vitro.

Circadian rhythmicity was studied by following the course of N-acetyl-transferase activity in the pineal glands of chickens in vitro. The results indicate (i) a daily change during day 1 of organ culture in constant dark that was dependent on the time the chickens were killed, (ii) equivocal persistence of the daily change in constant dark during 6 to 7 days of organ culture, (iii) an effect of light, (iv) inhibition by adrenergic agents and cycloheximide, and (v) stimulation by dibutyryl adenosine 3',5'-monophosphate and related compounds.

Acetyltransferases↗
PubMed1977

Timekeeping by the pineal gland.

N-Acetyltransferase, an enzyme involved in melatonin production in the pineal gland, exhibits a circadian rhythm in chickens with peak values in the dark-time and low values during the light-time, commencing at lights-on. When pineal glands of chickens killed during the dark-time (with high N-acetyltransferase activity) were organ-cultured, there was a decline in enzyme activity to light-time values. Regardless of the time of the dark at which the chickens were killed, the enzyme activity reached light-time levels at precisely the same time.

Acetyltransferases↗