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↗

PubMed1977

Implications of biologic rhythms for clinical practice.

The fact that many bodily functions display rhythmicity has an important bearing on resistance to toxins, response to drug or irradiation, and weight gain or loss according to when food is ingested. Though considerable clinical research remains to be done, "chronobiology" has already made available techniques for establishing predictable human rhythms, opening the way to more specific treatment of many condtions.

Adrenal Glands↗

PubMed1977

[Glossary of chronobiology (author's transl)].

Explore the source record for details and available documents.

Animals↗

PubMed1977

Survival and cure of leukemic mice after circadian optimization of treatment with cyclophosphamide and 1-beta-D-arabinofuranosylcytosine.

When cyclophosphamide and 1-beta-D-arabinofuranosylcytosine were administered to mice previously given injections of L1210 leukemia cells, the combination was more effective than either drug given alone. The effectiveness of the 2 drugs in combination was strongly influenced by the stage of the circadian system at which the drugs were administered. With the use of a chronobiological (sinusoidal) approach, in comparison with one or two conventional treatment schedules, it was possible to demonstrate an overall lower toxicity as monitored by death or weight loss. In general, mean survival times and cures (when obtained) were circadian stage dependent; for example, in 1 study the cure rate was 94% in mice treated at 1 circadian stage, but only 44% in those treated at another stage. It cannot be overemphasized, however, that just as the "right" timing can enhance (with statistical significance) both the tolerance to chemotherapeutic agents and the rate of cure in leukemic mice, so can the "wrongly" timed (wrongly placed) ara-C sinusoid or "wrongly" timed cyclophosphamide enhance toxicity and host death rate.

Animals↗

PubMed1977

Weight and metabolic changes induced by low carbohydrate-high fat diets in man and in rat.

Weight loss and potential toxicity of low carbohydrate-high fat diets were examined in 8 volunteer medical students given either a high fat diet or a high carbohydrate diet for 15 days, as well as in 36 Sprague-Dawley rats fed for 5 weeks a series of low carbohydrate diets (less than 1%), varying in protein and lipid proportions. A weight loss occurred with the low carbohydrate-high fat diets; serum cholesterol level increased in both man and rat; plasma triglycerides rose in man. In rat, we found an increase in hepatic lipid levels as in plasma ketone and non-esterified fatty acid concentrations. These effects seemed to be related to the increase in lipid intake rather than the lack of carbohydrates.

Adipose Tissue↗

PubMed1976

Timing of single daily meal influences relations among human circadian rhythms in urinary cyclic AMP and hemic glucagon, insulin and iron.

Relations among circadian rhythms in serum iron, glucagon and insulin and urinary cyclic AMP excretion differ drastically when diurnally active, nocturnally resting human adults consume all daily food for one week as breakfast only and for another week as dinner only - a finding of interest to diverse fields, e.g., for optimizing certain kinds of therapy or for a better utilization of calories.

Circadian Rhythm↗

PubMed1976

The circadian periodicity of urinary 17-ketosteroids, corticosteroids, and electrolytes in congenital adrenal hyperplasia.

The circadian periodicity of adrenal function in patients with congenital virilizing adrenal hyperplasia (CAH) was examined by measuring the urinary 17-ketosteroids, 17-hydroxycorticosteroids, sodium, and potassium. Patients with the salt-losing and the non-salt-losing types were studied with and without treatment. Cosine curves were fitted to the data by the least-squares method to determine the mesors, amplitudes, and acrophases of the variable for each patient. The data reveal distinct circadian rhythms for all variables measured whether or not the patient was receiving treatment. The acrophases for 17-ketosteroids and 17-hydroxycorticosteroids were between 1500 and 1800 h. These acrophases are about 6 h later than those for normal subjects. The treatment on a fixed daytime schedule for many years may have shifted the natural rhythm.

17-Hydroxycorticosteroids↗