The chronobiology of prostate-specific antigen (PSA): case report and chrono-metaanalysis

The circadian profiles of circulating PSA of a 72-year-old man (FH) and of 11 other clinically relatively healthy men are compared. The time course of FH's PSA was also followed longitudinally with single samples for over 3 years. A transient peak in PSA exceeding the upper time-unspecified age-corrected reference limit prompted a retrospectively premature biopsy which indicated prostatitis. Watchful waiting and additional PSA determinations may be the preferred approach before biopsy, notably in the elderly, for reasons of cost and invasiveness of the procedure. The load associated with a biopsy is also evaluated by a cardiovascular response.

7-year (circaseptennian) patterns in psychology and biology? Comment on Verhulst and Onghena

Nonlinear rhythmometry confirms a pattern of about 7 years, describing the number of births by birth year of quantum fathers reported by Verhulst and Onghena in 1996 and estimates the period to be 6.53 years with a 95% confidence interval overlapping 7 years. Other patterns of about 7 years are found in biology, as shown herein for the mean gonadal weight of an echinoderm (the purple sea urchin) and a mollusk (the black chiton). A number of periodic components with different frequencies, some shown to be genetically anchored, await applications in psychology as well as in other fields of medicine and biology.

Circadian and ultradian variation in pancreatic secretion of meal-fed pigs after weaning

We studied the time structure of pancreatic secretion in two experiments involving seven 6- to 7-wk-old intact male pigs, surgically fitted with a jugular vein catheter for blood sampling, pancreatic catheter, and a duodenal T-cannula for chronic pancreatic juice sampling for 72 h at 30- to 60-min intervals. Pigs were kept in metabolic cages in a regimen of 12 h of light alternating with 12 h of darkness and were fed at 0800, 1500, and 2200 daily a standard diet based on barley, soybean meal, and fish meal. Beginning 4 d after surgical recovery, three 24-h collections of pancreatic juice and blood sampling were begun either at 0700 or 0800 every 2nd d for 5 d. Pancreatic secretion exhibited a pattern characterized by distinct meal-related secretions of the first phase (postprandial), containing large amounts of protein and enzymes (trypsin and chymotrypsin), and by non-food-stimulated secretions of the second phase with less protein and enzymes. During the dark span, the first phase was practically absent; the response of the pancreatic secretion to the 2200 meal was not very pronounced. Apart from the anticipated circadian rhythm demonstrable by single cosinor analysis on a group basis, a prominent 8-h component was almost invariably statistically significant. Moreover, an approximately 3.43-h component was also prominent. These data indicate that pancreatic secretions are circadian periodic and that their response to a standard meal is also circadian-stage dependent. The circadian components may have been free-running because the pigs were adjusting themselves to the changing phase and that resulted in the period being different from exactly 24 h.

Studies on circadian periodicity of urinary corticoids in carcinoma of the breast

The circadian periodicity of urinary 17-ketogenic steroids (17-KGS), 17-ketosteroids (17-KS) and creatinine (Cr) was studied preoperatively and on the 9th postoperative day in 25 histopathologically proved breast cancer patients and in 15 healthy Indian women under tropical conditions. A statistically significant rhythm was observed in healthy participants for all three variables. Urinary corticoids were markedly elevated in breast cancer patients irrespective of the stage of the disease in comparison with healthy controls. The degree of elevation was more pronounced preoperatively in advanced stage breast cancer in comparison with other groups. After mastectomy, the values of all three variables declined markedly, approaching usual values with a circadian rhythm resembling the pattern found in clinical health.

About 8-hour variation of circulating human endothelin-1

Plasma endothelin-1 (ET-1) and cortisol were measured around the clock at hourly intervals on 7 clinically healthy, diurnally active, nocturnally resting subjects 22-27 years of age. The circadian rhythm in cortisol is demonstrated for each subject (p < or = 0.020) as well as on a group basis (p = 0.002), peaking in the morning. By contrast, the circadian variation of ET-1 is statistically significant in only one of the subjects, and it is not detected for the group as a whole (p > 0.20). Instead, ET-1 is characterized by an about 8-h component (p < 0.001) that is not found for cortisol.

Chronome assessment of circulating melatonin in humans

BACKGROUND

Melatonin (MEL) production occurs mainly during the dark span. A prominent circadian variation is demonstrated in both blood and urine in humans.

MATERIALS AND METHODS

The circadian, circannual, age and gender patterns of MEL were concomitantly investigated in 40 men and 132 women, each providing blood samples every 4 hours for 24 hours for conventional and cosinor analysis.

RESULTS

Circulating MEL is circadian periodic (P < 0.001), peaking at night. The MESOR (rhythm-adjusted mean) is higher in women than in men. The circadian amplitude decreases with age. Both are modulated by a circannual variation, the MESOR peaking in winter (P < 0.001) and the circadian amplitude in summer (P < 0.05).

CONCLUSIONS

Samples, unqualified as to gender, age and/or season, incompletely characterize the circadian MEL patterns. This chronome approach detects changes that may escape detection otherwise, checking whether a value is too high or too low, and also whether "swinging" occurs to the right extent.

The human blood pressure chronome: a biological gauge of aging

OBJECTIVE

This study examines changes in the broad time structure (chronome) of blood pressure (BP) as a function of age.

DESIGN

This is an observational study.

SETTING

The study was conducted at the Chronobiology Laboratories of the University oi Minnesota, Minneapolis, Minnesota.

PARTICIPANTS

Seventy-two individuals 12 to 106 years of age provided a 7-day record of BP measured indirectly with an ambulatory monitor, mostly at 15-60-minute intervals.

MAIN OUTCOME MEASURES

Amplitudes in least squares spectra at frequencies of 1 to 7 cycles per week and 1 to 8 cycles per day were analyzed by linear regression as a function of age. A two-way analysis of variance for subjects classified in four age groups tested for any variance transposition from the circadian (about-daily) to the infradian (frequency lower than one cycle per day) and/or to the ultradian (frequency higher than one cycle per day) domain.

RESULTS

The decreasing circadian BP amplitude with age is accompanied by an increase in infradian and ultradian prominence. The day-to-day variability in circadian characteristics also increases with age.

CONCLUSION

A variance transposition from the circadian to the neighboring ultradian and infradian domains characterizes the elderly human BP chronome, as a new, technically implementable biological, rather than chronological, gauge of human aging.

Rewards in practice from chrono-meta-analyses 'recycling' heart rate, ectopy, ischemia and blood pressure information

Previously published average curves of heart rate and duration of ischemia in patients with coronary artery disease, studied while on placebo or on treatment with either atenolol or diltiazem, are re-analysed for the assessment of about-daily (circadian) and about-weekly (circaseptan) changes in these variables and of any treatment effect on rhythm characteristics. In addition to circadians, a circaseptan pattern characterizes the duration of ischemia in all three aforementioned study stages. Both drugs decrease the duration of ischemia, atenolol, but not diltiazem, also affects the circadian amplitude and acrophase of this variable. A circaseptan pattern is also found for heart rate on placebo and on treatment with atenolol, but not with diltiazem. Both drugs lower heart rate and the circadian amplitude and 24-h standard deviation of heart rate, atenolol much more markedly than diltiazem. Circadian and circaseptan rhythm characteristics and their alterations with treatment serve to optimize treatment by timing its administration. Chronobiologic surveillance of variables that are being readily monitored as-one-goes by modern implantable devices can also serve for the validation of the effectiveness of drug and electrical therapy. Rhythm alterations, in turn, can provide the earliest warnings of an elevated disease risk and lead to an improved diagnosis.

Computer analysis of environmental temperature, light and noise in intensive care: chaos or chronome nurseries?

Lighting, noise and temperature were monitored in two perinatal nurseries. Rhythms of several frequencies were found, including prominent 24-hour rhythms with acrophases around 13:00 (light intensity) and 16:00 (noise). For light and noise, the ratio formed by dividing the amplitude of a 1-week (circaseptan) or half-week (circasemiseptan) fitted cosine curve by the amplitude of a 24-hour fitted cosine curve is smaller than unity, since 24-hour rhythms are prominent for these variables. The amplitude ratios are larger than unity for temperature in the newborns' unit but not in the infants' unit. Earlier, the origin of the about-7-day rhythms of neonatal physiologic variables was demonstrated to have, in addition to a major endogenous, also a minor exogenous component. Hence, the possibility of optimizing maturation by manipulating environmental changes can be considered, using, as gauges of development, previously mapped chronomes (time structures of biologic multifrequency rhythms, trends and noise).

Emphasis on the need for timing of autogenic training

The need for an individualized assessment of the blood pressure response to autogenic training based on longitudinal monitoring is commented upon with separate emphasis on the need for testing the effect of timing administration of autogenic training by stage of circadian rhythms and other pertinent components of a broader chronome (time structure).

Individual assessment of antihypertensive response by self-starting cumulative sums

A self-interpreted control chart, on an individualized basis, assesses the effect of a switch from beta-blockers to an angiotensin-converting enzyme (ACE)-inhibitor in a patient with occasional blood pressure (BP) excess. In dense and long data series, the BP and heart rate (HR) of this patient respond to the change in treatment by the test criterion of a self-starting Cumulative Sum (cusum), which reaches values outside a decision interval with a lowering of BP and an increase in HR and vice versa, at least for BP, after treatment cessation. Thereafter, minimal sampling requirements are sought in the same data by applying the same control chart approach to decimated data. Skeleton sampling schemes in a system of chronobiologic self-analysis and interpretation of manually recorded data obtained at strategically placed times (established on the basis of data decimations) could complement control charts that are used on a home computer or preferably would be built into the output of ambulatory monitors used at the outset as a minimum and routinely as an optimum.

Endothelin-1's chronome indicates diabetic and vascular disease chronorisk

Plasma endothelin-1 was measured around the clock in 72 subjects. Cosinor methods were used to assess circadian and other recurrent variation and trends, that is, the time structure (chronome) of this peptide. Multifactorial analyses of variance and linear regressions assessed chronome alterations associated with different risk factors: diabetes, obesity, high cholesterol, high blood pressure, vascular disease, smoking, and age. The rhythm-adjusted mean (MESOR) of endothelin-1 is elevated in diabetes and vascular disease. Diabetes is also associated with a larger circadian amplitude. A circadian variation in a subgroup of low-risk subjects is modulated by components with both lower and higher frequency.

About-half-weekly (circasemiseptan) component of the endothelin-1 (ET-1) chronome and vascular disease risk

Plasma ET-1 was measured around the clock on different calendar dates in healthy subjects and in subjects with diabetes and/or with high blood pressure and/or a history of vascular complications (HVDR). A transverse approach, with each subject contributing a single 24-h mean, assessed any about-weekly or half-weekly variation in ET-1. A circasemiseptan component resolved by single cosinor for nondiabetic (but not for diabetic) HVDR subjects (p = 0.010) differs in its timing of overall high values (p < 0.050) from that found in healthy subjects (p = 0.006). The results are aligned with circasemiseptan patterns in other circulatory variables and morbidity/mortality statistics.

Excessive circadian amplitude of blood pressure increases risk of ischaemic stroke and nephropathy

After 48-h ambulatory blood pressure monitoring, the incidence of ischaemic stroke, nephropathy, coronary heart disease and retinopathy was prospectively assessed for 6 years in 297 subjects, including 176 treated patients with an elevated blood pressure mean (MESOR-hypertensives). The relative risk associated with an excessive circadian blood pressure amplitude is 8.2 (95% confidence interval 3.1 to 21.7; p < 0.001) for ischaemic stroke and 6.9 (2.9 to 16.3; p < 0.001) for nephropathy. In MESOR-hypertensives, the relative risk for ischaemic stroke and nephropathy is 6.3 (p < 0.005) and 4.0 (p < 0.05), respectively. In MESOR-normotensives as well, an excessive circadian blood pressure amplitude is associated with a large increase in risk for ischaemic stroke and nephropathy (p < 0.05). An excessive circadian blood pressure amplitude is an entity in its own right that increases the risk of adverse vascular events irrespective of the blood pressure MESOR, age and the presence of other known risk factors. The diagnosis of this condition requires around-the-clock monitoring of blood pressure. The treatment of patients with this condition should aim not only at lowering the blood pressure mean but also at reducing blood pressure variability within 24 h.

Chronobiometric assessment of autogenic training effects upon blood pressure and heart rate

Autogenic training, a method of self-hypnosis, lowers the extent of within-day variation of systolic blood pressure assessed by the circadian double amplitude. The blood pressure and heart rate of ten patients, conventionally diagnosed as having hypertension or white-coat hypertension, were automatically monitored at 30-min intervals for 7 days before autogenic training and again for 7 days, at 1 or 2 months after the start of autogenic training (practiced three times daily). The circadian double amplitude of systolic blood pressure of the patients investigated was 3 to 17 mm Hg lower on autogenic training. In 5 patients, reductions by 7 to 17 mm Hg were statistically significant. These results are regarded as provisional statistics, the utility of which depends on replication. By contrast, the over-all group reduction of the circadian double amplitude of systolic blood pressure by 8 mm Hg on the average can be taken at face value. Autogenic training also lowered the circadian double amplitude of diastolic blood pressure, but the effect was small as was the effect of autogenic training upon the MESOR (a rhythm adjusted mean) and acrophase (a measure of the timing of over-all high values recurring each day). The effect of autogenic training upon the circadian double amplitude of systolic blood pressure suggests its trial as first-line treatment of patients with an excessive circadian blood pressure amplitude, a condition which, even in the absence of an elevated 24-hr, average of blood pressure, is associated with a large increase in the risk of developing ischemic stroke or nephropathy.

Changes in human blood pressure with season, age and solar cycles: a 26 year record

The record was studied of a 71-year-old, diurnally active (0700-2200 hours) male psychiatrist (G.N.) who self-measured systolic and diastolic blood pressure (BPS and BPD) mostly but not exclusively on Sunday mornings, from 1969 to 1994. A large about-yearly change was revealed which increased with age and was accompanied by a decreasing trend in the yearly rhythm-adjusted mean (MESOR; P < 0.01). According to conventional criteria that specify only upper limits of acceptability, G.N. was hypertensive in summer and normotensive in other seasons. Since changes in both MESOR and circannual amplitude occurred, a systematic surveillance of BP is the chronobiological recommendation.

Clinical relevance of about-yearly changes in blood pressure and the environment

Changes identified by inferential statistics from summer to winter of high to low arterial blood pressures (BP) have been quantified as a large predictable about-yearly BP swing. This condition of a large annual BP amplitude (LABPA) raises concern about hypotension as well as hypertension and raises new questions regarding appropriate guidelines for diagnosis and treatment. Recommendations made in the fall on the basis of data collected in the summer may be totally inadequate in dealing with the patient's condition in the winter. In order to avoid such mistakes, it is imperative to implement a systematic surveillance of BP in the light of current chronobiological limits. Patients with a large circannual BP amplitude are particularly suited for a study of the underlying hormonal mechanisms. The longitudinal monitoring of their BP is also amenable to the study of environmental influences from near and far.

The circadian rhythm of cortisol in the saliva of young pigs

Single and population-mean cosinor analyses document a circadian rhythm in salivary cortisol of pigs (p < 0.001). The midline estimated statistic of rhythm, the MESOR (M), is 1.50 +/- 0.07 ng/ml. For the group of 14 pigs studied there was a predictable variation of 64% around this mean in salivary cortisol within a day: the double circadian amplitude, 2A, was 0.96 ng/ml, with a 95% confidence interval ranging from 0.60 to 1.32 ng/ml. A measure of timing, the acrophase, phi, was 10 h 52 min from the phase reference (0030, the middle of the daily dark span of the 24-h light-dark cycle in which the pigs were kept). The 95% confidence interval of phi extended from 9 h 48 min to 12 h 12 min from the reference time. The chronobiologic approach provides indispensable quantitive characteristics as reference standards for future basic or applied work.

Evidence from a chronobiometric approach that chronic smokers, although normotensive, show an increase in diurnal blood pressure

OBJECTIVE

To investigate the effects of chronic smoking on the 24 h blood pressure and heart rate pattern in normotensive subjects.

METHODS

Twenty-five smokers and 25 age-, weight- and height-matched non-smokers, who were all clinically healthy young men, gave their informed consent to undergo non-invasive, automated, ambulatory blood pressure monitoring for 24 h. The smokers in this study consumed on average 25.4 cigarettes per day. The lifestyle of the two groups was comparable because they worked as clerks at the same company. The 24 h blood pressure and heart rate data were analysed according to chronobiological methods.

RESULTS

Smokers were found to show a statistically significantly higher blood pressure versus non-smokers by day but not by night. Furthermore, smokers showed a slight increase in the mean level of circadian blood pressure rhythm versus non-smokers, accompanied by an amplification of one cyclic component of this periodicity.

CONCLUSIONS

The increase in diumal blood pressure in smokers might be regarded as the haemodynamic effect of chronic smoking in normotensive subjects. Such an effect seems to be substantiated pathophysiologically by an amplitude overmodulation of one of the harmonic components which confer the circadian blood pressure rhythmicity. Because the diumal increase in blood pressure persists for two-thirds of the day-night period, one can argue that this phenomenon in normotensive smokers might be a premonitory sign of future hypertension. Apart from this, one can hypothesize that the diumal increase in blood pressure might itself be a cause of target organ damage, given its consistent within-day duration and daily repetition.

Circadian rhythm of blood pressure and life style: a study of clinically healthy subjects living in rural and industrialized countries

The aim of this study is to investigate how the blood pressure (BP) circadian rhythm (CR) is influenced by life style. Two groups of subjects were recruited from Nepal and Japan because of the extremely different occupational routines of these countries. The Nepalese represent a rural culture, while the Japanese reflect an industrialized civilization. Both the ethnic groups have in common a high dietary sodium intake. The BP monitoring was estimated according to chronobiological methods. Results provide evidence for a phase difference in BP CR which is coherent with the life style in the two groups. Furthermore, the estimates demonstrate that the Japanese show a higher level in daily BP which is related to the greater number of hours in which they are active. These findings may be taken into account for better deciphering of what is the role of life style on BP physiology in human beings.

Core body temperature and circadian rhythm of hot flashes in menopausal women

Postmenopausal hot flashes are characterized by sweating and peripheral vasodilation and occur more frequently during increased heat loads. The circadian rhythm of core body temperature (TC) is well known and suggests that hot flashes will be most frequent when core temperature is highest. This hypothesis has not been tested previously. Ten symptomatic and six asymptomatic postmenopausal women were recruited from advertisements and screened. Each received 24-h ambulatory monitoring of sternal skin conductance levels to detect hot flashes, ambient temperature, skin temperature, and TC. The last measure was recorded using an ingested radiotelemetry pill. Cosinor analysis demonstrated a circadian rhythm (P < 0.02) of hot flashes with a peak at about 1825 h. TC values of the symptomatic women were lower than those of the asymptomatic women (P < .05) from 0000-0400 h and at 1500 and 2200 h. The majority of hot flashes were preceded by elevations in TC. Thus, elevated TC may serve as one trigger of menopausal hot flashes.

X-irradiation chronosensitivity and circadian rhythmic proliferation in healthy and sarcoma-carrying rats' bone marrow

Mitotic activity of bone marrow and tumor of sarcoma-bearing rats and of bone marrow of healthy controls is circadian periodic. Whereas the circadian rhythm in mitotic activity of bone marrow is similar for intact and tumor-bearing rats, with a peak occurring shortly after the onset of the dark (activity) span, the circadian rhythm in mitotic activity of tumor has a much smaller amplitude and a different acrophase occurring late in the dark span. This difference in acrophase of mitotic activity of bone marrow and tumor has important implications for scheduling the administration of oncotherapy. For the tumor model examined herein, it suggests the possibility to achieve concomitantly near maximal efficacy and near minimal myelotoxicity, a result awaiting further investigation in humans with different kinds of malignancies.

Toward salivary-urinary chronosensitivity testing: chronomes of OVX1, M-CSF and CA130

Several rhythmic components were previously mapped for salivary and/or urinary CA125 and CA130. On the background of such reference standards, OVX1 and M-CSF were assayed on 242 urine samples and 160 saliva samples provided by a 71-year-old patient with a Müllerian/ovarian adenocarcinoma. Serum OVX1 correlates with serum CA125 (P = 0.002); when circulating CA125 concentrations decreased (from 122 to 14 U/ml), the urinary excretion rate of OVX1 decreased (P = 0.005), whereas the urinary excretion rate of CA125 increased (P < 0.001). Salivary OVX1 and urinary M-CSF show ultradian variations (with a frequency of one cycle in 14-17 hours), which could be utilized to guide treatment timing targeted first to optimize treatment efficacy and as a second consideration to minimize treatment toxicity.

Chronome of urinary 6-sulfoxy-melatonin excretion, circulating CA125, cancer progression and therapeutic response

The longitudinal follow-up of a patient with an advanced adenocarcinoma of the ovary sheds new light on the involvement of the pineal in carcinogenesis. The changes in the circadian MESOR of 6-sulfoxy-melatonin following a course of chemotherapy may differ in relation to the success or failure of treatment, yet the MESOR does not correlate with tumor burden assessed by circulating CA125. By contrast, the ratio of circaseptan-to-circadian amplitudes involving two chronome components correlates with the cancer marker. To that extent, the study reveals a critical about 7-day (circaseptan) aspect of the pineal involvement in cancer progression. This information could be exploited in designing schedules of melatonin administration to cancer patients.

Studies on circadian periodicity of plasma 17-hydroxycorticosteroids (17-OHCS) in carcinoma of the breast

Circadian periodicity of plasma 17-hydroxycorticosteroids (17-OHCS) was studied in 25 histopathologically proved breast cancer patients pre operatively and on the 9th postoperative day and in 15 healthy women under tropical conditions. A marked rhythm in plasma 17-OHCS concentration was noticed in healthy controls. The maximal concentration occurred at 06:00 followed by a consistent decline throughout the daytime, reaching a minimum at 00:00 with an amplitude statistically significantly different from zero and an acrophase around 08:56. The plasma 17-OHCS concentration was found to be elevated at all sampling hours in breast cancer patients, irrespective of the stage of the disease. However, the degree of elevation and disruption of rhythm was more pronounced in advanced sages, preoperatively, in comparison to other groups. Moreover, the values declined markedly at all collection hours after mastectomy, approaching usual values and rhythm characteristics on the 9th postoperative day.

Spectral differences between epitopes in the cronomes of salivary CA130 and CA125

Ovarian tumor markers CA125 and CA130 are here investigated in the search for harbingers of an elevated cancer risk or pre-cancer. A circadian rhythm of large amplitude is demonstrated for salivary CA125 and CA130 of a clinically healthy 28-year-old woman (AP). The circadian rhythms of both markers found in AP have a pattern similar to that of a patient (EH) with a müllerian cancer involving the ovary, with high values in the early morning and low values in the afternoon. Whereas acrophases occur approximately at the same circadian stage in both AP and EH, the MESOR and circadian amplitude are higher in EH as compared to AP. The circadian rhythm of salivary CA130 of AP is similar to that of other clinically healthy women. CA130 concentrations are lower than CA125 concentrations in unstimulated saliva (before rinsing of the mouth) in this clinically healthy woman (AP), and in other women studied herein. This difference between CA130 and CA125 concentrations is observed irrespective of circadian stage and irrespective of the concentration range of CA125 at the outset. After rinsing of the mouth, a statistically significant decrease in both CA130 and CA125 concentration is observed in AP and in another healty woman (GC) who collected saliva both before and after rinsing of the mouth.

Circadian rhythm of sister chromatid exchanges in human chromosomes

Since sister chromatid exchange (SCE) relates directly to DNA synthesis which is circadian periodic, this study examines whether a circadian rhythm also characterizes SCEs. In 4-hourly blood samples collected for 48 hours on three diurnally active, nocturnally resting subjects with no family history of chromosome aberrations or instability, a circadian rhythm is demonstrable with an acrophase occurring around 14:45. The circadian amplitude is only of the order of 10% of the MESOR in untreated cultures or in cultures exposed to cefodizime. It remains more or less unchanged in cultures exposed to mitomycin-C, while the MESOR increases by about a factor of 2. In studies of human chromosome aberrations, the circadian rhythmicity of SCE should be taken into consideration.

Toward a chronome of superfused pike pineals: about-weekly (circaseptan) modulation of circadian melatonin release

In continuous darkness for about 5.5 days in eleven replications, the pineal shows neither only a decreasing trend nor only a damped circadian rhythm; there is an infradian modulation: after an initial decline, melatonin production increases again, with a pattern compatible with the assumption, for at least one cycle, that a built-in pineal "week" has a larger extent of predictable change than that of a pineal "day". Melatonin release from the isolated pike pineal reveals a circadian rhythm which, on the average, is damped, but demonstrable in the second half of a time series covering 5.5 days (P < 0.05). At fixed environmental temperatures of 10, 15, 19 or 20 degrees C (the latter two pooled), single and population mean cosinor analyses reject the assumptions of zero circaseptan and circadian amplitudes in the chronome of the pineal from the pike (Esox lucius L.). The circaseptan pattern is confounded by possible trends. The time series analyzed are brief, yet validate, by a one-way analysis of variance in plexograms as well as by cosinor, an about-weekly pattern, if not (yet) rhythm, on the basis of 745 determinations. The circaseptan- and circasemiseptan-to-circadian amplitude ratios are numerically larger than unity, on the average (2.014; 95% confidence interval, CI: 1.120 to 3.641 and 1.107; CI: 0.724 to 1.693, respectively). A positive correlation of the urinary excretion rate of a major breakdown product of melatonin of a cancer patient with a circulating cancer marker serving as a gauge of disease progression lends an oncologic perspective to the amplitude ratios of melatonin release in vitro here reported.(ABSTRACT TRUNCATED AT 250 WORDS)

Chronobiologic aspects of urinary gonadotropin peptide (UGP)

When using urinary gonadotropin peptide (UGP) as a marker for ovarian cancer, a circadian rhythm of large amplitude is best assessed for improving preanalytic quality control, for specifying how often and when to sample and for resolving chronobiologic endpoints. In a patient (EH, 73 y) with an ovarian (Müllerian) adenocarcinoma, overall high UGP values occurred consistently around 07:00 (standard deviation, SD = 2 h), similar to the timing observed in a presumably healthy woman. The circadian rhythm of EH averages in amplitude about 45% of the daily mean value (SD = 15%). The results indicate the desirability of deriving time-specified reference limits in health for an improved diagnostic value of UGP. The circadian UGP pattern awaits tests of applications for a chronodiagnosis of ovarian cancer, for optimizing treatment efficacy by timing according to rhythms, and conceivably for detecting earliest precancer risk.

Circasemiseptan (about-half-weekly) and/or circaseptan (about-weekly) pattern in human mitotic activity?

This review and metachronanalysis was prompted by the presence of a circasemiseptan pattern (P < 0.05) found by population-mean cosinor in published data characterizing murine malignant growth after treatment with cyclophosphamide (1-4). For cancer chronotherapy (5-9), the analyses serve to suggest the desirability to extend the focus beyond circadian aspects of drug timing and drug effect to a broader view that takes into account as much of the body's make-up in time as is practical. Among the different components of a chronome (the time structure of rhythms with different frequencies and trends in a given variable), the 3.5-day patterns (circasemiseptans) and the 7-day patterns (circaseptans) are more readily accessible to measurement and thus to manipulation and optimization than infradians with even lower frequencies; they may also be pertinent to the scheduling of infusions covering several days, particularly those using drug administration devices, some of which are programmable. Should circaseptans and circasemiseptans characterize the host as well as the tumor, the drug administration schedule could be optimized for both treatment efficacy and host tolerance, with a view of infradian as well as of circadian and ultradian rhythms.

Cancer marker assessment: case report on salivary and urinary CEA

A circadian rhythm is demonstrated for salivary CEA in a clinically healthy man who collected unstimulated saliva samples around the clock for 4 days. Its acrophase occurs around 07:00, slightly later than for patients with colon cancer. A circadian rhythm of borderline statistical significance is found for the urinary excretion rate of CEA determined during the same span by this patient. It has an acrophase occurring around 15:00, differing from that of salivary CEA. Although CEA may have only limited value to assess tumor burden, even when determined in blood, rhythm characteristics of tumor markers such as CEA await applications for guiding treatment timing and for detecting earliest chronome alterations not only in the case of an overt cancer but as a feature of predisease and/or disease risk elevation.

Metachronanalysis of circannual and circasemiannual characteristics of human suprachiasmatic vasopressin-containing neurons

We here test for and detect anticipated about-yearly (circannual) changes in the volume and number of vasopressin-containing neurons in the human suprachiasmatic nucleus. We then resolve inferential statistical parameters quantifying the extent and timing (the amplitude and acrophase) of the circannual rhythm previously missed by data inspection and classical biometry. We parametrize about-half-yearly changes previously validated by non-parametric statistical tests. New dynamic circannual and circasemiannual endpoints thus become available for basic investigation and the assessment of disease risk elevation and/or chronoprotopathology. It was earlier demonstrated that the circannual rhythms of prolactin and TSH are prominent classifiers of individuals at high versus low familial and other risk for developing breast or prostate cancer. Any neurocrine or neural mechanisms contributing to this classification are now amenable to study, on a population basis, with the dynamic hypothalamic rhythm characteristics yielded by this metachronanalysis.

Physical chemistry and the biologic week in the perspective of chrono-oncology

The computation of spectra and cross-spectra yielding coherences suggests that there exist certain relationships between rhythmicities and electromagnetic fields that are external to the biologic structure studied. Models are here provided which may prompt further investigation by allowing at least tentative, quantitative temporal insights into physico-chemical aspects of the biologic week. On the basis of empirical data, a computation of the oscillating frequency during the diffusion of ions in a magnetic field can be performed. The frequency of some ions found in cells (Ca2+, K+, Na+, Mg2+) and of some proteins (albumin, hemoglobin) can be calculated given the diffusion constant in cells, the magnetic field strength, the relative molecular mass and the effective charge. For a field of 10(-9) Tesla, the oscillating period of K+ is about 180 hours, that of Ca2+ about 160 hours, that of Na+ about 150 hours and that of Mg2+ about 145 hours; the period lengths of albumin and hemogiobin are of the order of 30 and 40 days. Without a consideration of any receptors, the results seem to represent, at least numerically, realistic components in the time structure investigated by chronobiology.

Chronometaanalysis: circasemiseptan (3.5-day) pattern in mitotic activity of murine sarcoma after treatment with cyclophosphamide

This note focuses attention upon infradians in mitotic activity of a murine sarcoma. Starting on day 8 after the inoculation of mice with a sarcoma, three different doses of cyclophosphamide, one dose at three different circadian times, were injected and tumor was sampled with serial independence, mostly at 12-hour intervals during the 4 ensuing days. A metachronanalysis of these heterogeneous data, collected for a different purpose with different doses and at different circadian times, reveals the presence of a circasemiseptan pattern (P < 0.05 by population-mean cosinor). Without a longitudinal replication, the result is described only as a pattern rather than as a (recurring) rhythm, characterizing malignant growth after treatment with cyclophosphamide. For cancer chronotherapy, the analyses serve to suggest the desirability to replace exclusive focus upon circadian aspects of drug timing and drug effect by a broader view that takes into account as much of the chronome as is practical. Among the different components of a chronome (i.e., the time structure of rhythms with different frequencies and trends in a given variable), the circasemiseptans (and circa-septans) are more readily accessible than infradians with even lower frequencies; they may also be pertinent to the scheduling of infusions covering several days, particularly those using drug administration devices, some of which are programmable. Since circaseptans and circasemiseptans may characterize the host as well as the tumor, infradian drug administration schedules could be sought that optimize both treatment efficacy and host tolerance.

From Pavlov's time coding and conditioned reflexes to a chronophysiology of human nutrition

Chronobiology, including chronophysiology, is now a hot area of multidisciplinary research. The paper outlines the contribution of I. P. Pavlov's ideas concerning time coding and time structures; conditioning is considered as a full account of how rhythms come about. Are mentioned some principals and advances of chronobiology and chronobiometry, with special emphasis on the chronophysiology of digestion. Finally is reminded the motto of quantitative chronobiology "measure what is measurable in time, hence meaningfully, and render equally significantly measurable what as yet is not."

Broad scope of a newly developed actometer in chronobiology, particularly chronocardiology

The scope and the details of a newly developed actometer were introduced. We are able to select a desired threshold of gravity(g)-forces between 0.01g and 0.50g and to simultaneously monitor 3 kinds of activity along with an averaged g-force every minute. As a routine study, we monitored at settings of 0.01g, 0.05g and 0.20g and averaged on one channel. Part of the time, physical activity was monitored together with ambulatorily monitored blood pressure (BP) and the ECG, or at least heart rate (HR). Physical activity showed a circasemiseptan and circaseptan periodicity as well as the circadian component, especially in subjects with an irregular sleep-wakefulness life style. On the average, physical activity was greater on a working day than on a holiday. Everyday physical activity reflects in part the ability to exercise, and it is expected that this actometer can contribute or provide an objective individualized quality-of-life index. The effect of physical activity on circadian profiles of BP, HR and HR variability is also examined. We observed that BP started to increase several hours before getting up. This fact likely shows that there is an endogenous circadian rhythm in BP, independently of the sleep-wakefulness cycle. Lastly, we investigated the relationship between physical activity and HR in patients permanently paced; we confirmed that the DDDR pacing mode was more physiological than the VVI or VVIR mode. This newly developed actometer will bring about further progress in chronobiology.

Ultradian-infradian variation of cardiac creatine phosphokinase (CPK) activity in male Holtzman rats

Reference standards were sought for use in the search of any indications of myocardial damage by an alteration of the time structure, or chronome, of creatine phosphokinase (CPK) "MB" isoenzyme activity in the heart of the male Holtzman rat. 144 rats were kept on 6 lighting regimens staggered by 4 hours, 24 rats per chamber. On 8 consecutive days, hearts from 3 animals from each chamber were harvested and weighed. The left ventricle was dissected, homogenized in a buffer solution at 4 degrees C and stored frozen at -20 degrees C until analysis. A supernatant aliquot of each sample was analyzed by a discontinuous gradient elution from DEAE-Shephadex A-50 columns. The CPK isoenzymes were quantified by the Rosalki method. Results of the CPK assay from each time point were analyzed by linear and nonlinear least-squares rhythmometry. Among other components, a 168h or circaseptan rhythm characterized CPK activity in the heart of Holtzman rats. This component and other ultradian and circadian aspects of the time structure of rhythms and trends, the chronome of a given variable, may serve, by any eventual alteration of their dynamic characteristics, as gauges of potential cardiac damage prior to the occurrence of an increase in the overall mean of the enzymatic activity.

Heart rate and blood pressure chronomes during and after pregnancy

Whereas conventional time-unspecified single measurements of blood pressure and heart rate may mislead, influenced as they are, among other factors, by the individual's emotional state, position, diet and external stimuli generally, the chronobiologic evaluation of predictable variability in these physiologic variables assesses early cardiovascular disease risk in pregnancy by (a) the use of fully ambulatory devices and (b) the proper processing of the time series thus obtained. We have used this approach to quantify changes in 24-h synchronized circadian characteristics of cardiovascular variables in two consecutive pregnancies of a clinically healthy woman. The results were then compared with those obtained from data sampled after the second pregnancy. Blood pressure and heart rate were automatically monitored, at 1-h intervals, each time for at least 48 consecutive hours, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of those circulatory variables were computed for each 48-h profile of measurements by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian rhythm-adjusted means and amplitudes with gestational age. In both pregnancies, the predictable variability of the circadian rhythm-adjusted mean of blood pressure can be approximated by a second-order polynomial model on gestational age: a steady linear decrease in systolic, mean arterial and diastolic blood pressures up to the 22nd week of pregnancy is followed by an increase up to the day of delivery. This pattern of variation is not found for data similarly sampled during non-pregnancy on the same woman. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure and heart rate and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.

Cross-spectral coherence between geomagnetic disturbance and human cardiovascular variables at non-societal frequencies

A 35-year-old cardiologist monitored himself with an automatic ABPM-630 (Colin Electronics) monitor, mostly at 15-minute intervals around-the-clock for three years with a few interruptions. In this subject with a family history of high blood pressure and stroke, a cross-spectral analysis revealed a statistically significant coherence at 27.7 days between systolic and diastolic blood pressure and heart rate vs. the geomagnetic disturbance index, Kp. A lesser peak in coherence was found for systolic blood pressure with Kp at a trial period of 4.16 days (P = 0.046). These results suggest that changes in geomagnetism may influence the human circulation, at least in the presence of familial cardiovascular disease risk, and they may do so at frequencies that have no precise human-made cyclic worldwide match.