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Biomedical subjects

F Halberg

Publications and source records attributed to F Halberg.

At least 19 recordsLinked to original sources
PubMed1979

Circadian variation in urinary melatonin in clinically healthy women in Japan and the United States of America.

Urinary melatonin excretion is lower in East-Asian (Japanese) than in North-American (whites of mixed ethnic origin) women. Moreover, a statistically significant circadian rhythm is demonstrated by population-mean cosinor in the data pool from both groups of women. Furthermore, statistical significance characterizes interactions of effects from geographic differences (between ethnic groups) with temporal factors. Such spatio-temporal interactions await further scrutiny with a view inter alia of carcinogenesis as it is influenced by a spectrum of intermodulating rhythms.

Adult↗
PubMed1979

Circannual rhythms in progesterone receptor levels and functions.

Studies in this laboratory on the nuclear binding sites (acceptors) for progesterone receptor in the developed chick oviduct have resulted in the detection of seasonal variations in the levels and functions of the receptor. Cytosol preparations obtained from the chick oviducts during the winter/spring period between January and May display reduced receptor levels as well as a loss of the capacity of the receptor to bind to nuclear "acceptor" sites in vitro. The binding of [3H]P-R to whole chromatin or purified acceptor proteins reannealed to DNA display the same rhythm. No such rhythm is detected for the binding of P-R to pure DNA. Computer analysis of the data, using least squares method to fit the data to cosine curves, shows a significant fit indicating a circannual rhythm in P-R binding to the acceptor protein-DNA complex but not to pure DNA. The nuclear binding in vivo, achieved by injecting [3H]progesterone into the wing vein and analyzing the radioactivity localized in the oviduct nuclei, also displays a similar rhythm. These results support that native nuclear acceptor sites for progesterone in the chick oviduct represent protein-DNA complexes and not pure DNA. The failure of P-R to bind the nuclear acceptor sites in vivo and in vitro during this period can be explained by the two subunit hypothesis of Schrader and O'Malley, whereby one of the two subunits is absent or inactive during this period.

Animals↗
PubMed1979

Rhythmometry gauges treatment of mesor-hypertension in the seventh and eight decades of life.

Autorhythmometry of blood pressure by an individual over an age-span of 67 to 72 years showed a strong circadian rhythm superimposed upon significant circaseptan and circannual rhythms. Automatic BP monitoring with an Arteriosonde throughout 24-hour spans on 4 separate occasions, before and during treatment, also indicated a prominent circadian BP rhythm and a treatment-related reduction in circadian mesor. The concept of a blood pressure mesor reference for the antimesor-hypertensive treatment constitutes a valuable guideline in the control of "familial" mesor-hypertension.

Aged↗
PubMed1979

Schedule shifts, life quality and quantity--modeled by murine blood pressure elevation and arthropod life span.

During the span from 50 to 100 days and beyond, the male stroke-prone Okamoto rat develops systolic blood pressure measures in excess of 200 mm Hg. In the course of developing such a marked elevation in systolic blood pressure mean, this intermittently handled male Okamoto rat exhibits a statistically significant circadian rhythm with large amplitude. This amplitude may represent, at least in part, a response to intermittent handling; it is several times larger than the amplitude for spontaneously mesor-hypertensive (but not stroke-prone) female animals of the same age.

Aging↗
PubMed1978

Time-qualified reference intervals - chronodesms.

Methods are presented for qualifying clinical reference intervals, for individuals as well as peer groups, according to circadian and other rhythms, using chronobiologically-defined single samples or time series.

Biological Clocks↗
PubMed1978

[Circadian periodicity and stomach ulcer. An animal experiment model for the detection of rhythm factors in the genesis of civilization diseases].

Against the background of clinical experience attesting to the role of the circadian and circannual rhythm stage in gastric ulcerogenesis, animal experiments provide a model where by circadian stage and sex are both revealed as determinants of gastric ulcerogenesis. Experiments on the genetically mesor-hypertensive Okamoto rat demonstrate the critical interaction of multiple loads in ulcerogenesis, in keeping with a report by Glavin and Mikhail. While stimulation by single loads of a certain intensity--immobilization, food deprivation or cooling--did not regularly lead to the production of gastric ulcers, the combination of these same loads did so as a function of circadian state at the beginning of exposure time.

Animals↗
PubMed1978

Chronobiologic optimization of aging.

Chronobiologic facts, concepts and methods are relevant to gerontology and geriatrics. Circadian and other rhythms are prominent sources of predictable variation requiring a reassessment of the "normal range" at all ages. Changes in the characteristics (e.g., the amplitude) of these rhythms during aging emphasize the need for careful evaluation of time dependency in research and clinical practice. Manipulation of periodic environmental factors that synchronize circadian rhythms can affect lifespans in plants and animals, further supporting the suggestion of an interaction between rhythms and senescence.

Aged↗