Hormone and cytokine circadian alteration in non-small cell lung cancer patients.

Alterations in hormone secretion and cytokine levels have been evidenced in many neoplastic diseases. In this study we have evaluated the circadian profile of growth hormone (GH), insulin-like growth factor-1 (IGF-1), interleukin-2 (IL2), melatonin (MEL) and cortisol (COR) serum levels in non-small cell lung cancer patients. Blood was sampled every 4 h for 24 h in 11 healthy (H) men (ages 35-53 years) and 9 men with stage 2, 3 or 4 non-small cell lung cancer (C) (ages 43-63 years). Serum GH, total IGF1, IL2, MEL and COR were measured and examined for group differences, trends, and rhythm characteristics. 24-h means were significantly higher in C234 vs H for GH, GH/IGF1, IL2 and COR, and lower for IGF1, but IL2 and COR were not different for C23 vs H. A linear regression across 4 groups (H, C2, C3, C4) found a positive trend for COR, GH, GH/IGF1 and IL2, and a negative trend for IGF1. A linear regression run between the 24-h mean levels of GH, IGF1, COR, MEL and IL2 in healthy subjects evidenced a statistically significant positive trend between MEL and GH (R = 0.281, p = 0.022) and in cancer patients showed a statistically significant negative trend between GH and IGF1 (R = 0.332, p = 0.01), COR and IGF1 (R=0.430, p=0.001), and a statistically significant positive trend between the 24-h mean of COR and GH (R = 0.304, p = 0.02). Rhythms in MEL and COR (peaks near 01:00h and 08:00h, respectively) indicated identical synchronization to the light-dark cycle for both groups. A circadian rhythm was detected in GH and GH/IGF1 for C23 and H, with IGF1 and IL2 non-rhythmic in any group. In conclusion, an increasing trend and progressive loss of circadian rhythmicity in GH and GH/IGF1, an increasing trend in cortisol and IL2, and a decreasing trend in IGF1 in C, reflect a complex chain of events that could be involved in progression of neoplastic disease. A therapeutic strategy needs to take into account circadian patterns and complex interactions of the multiple functions that characterize the hormone and cytokine levels in the frame cancer progression.

Time-related dynamics of variation in core clock gene expression levels in tissues relevant to the immune system.

Immune parameters show rhythmic changes with a 24-h periodicity driven by an internal circadian timing system that relies on clock genes (CGs). CGs form interlocked transcription-translation feedback loops to generate and maintain 24-h mRNA and protein oscillations. In this study we evaluate and compare the profiles and the dynamics of variation of CG expression in peripheral blood, and two lymphoid tissues of mice. Expression levels of seven recognized key CGs (mBmal1, mClock, mPer1, mPer2, mCry1, mCry2, and Rev-erbalpha) were evaluated by quantitative RT- PCR in spleen, thymus and peripheral blood of C57BL/6 male mice housed on a 12-h light (L)-dark (D) cycle and sacrificed every 4 h for 24 h (3-4 mice/time point). We found a statistically significant time-effect in spleen (S), thymus (T) and blood (B) for the original values of expression level of mBmal1 (S), mClock (T, B), mPer1 (S, B), mPer2 (S), mCry1 (S), mCry2 (B) and mRev-Erbalpha (S, T, B) and for the fractional variation calculated between single time-point expression value of mBmal1 (B), mPer2 (T), mCry2 (B) and mRev-Erbalpha (S). A significant 24-h rhythm was validated for five CGs in blood (mClock, mPer1, mPer2, mCry2, mRev-Erbalpha), for four CGs in the spleen (mBmal1, mPer1, mPer2, mRev-Erbalpha), and for three CGs in the thymus (mClock, mPer2, mRev-Erbalpha). The original values of acrophases for mBmal1, mClock, mPer1, mPer2, mCry1 and mCry2 were very similar for spleen and thymus and advanced by several hours for peripheral blood compared to the lymphoid tissues, whereas the phases of mRev-Erbalpha were coincident for all three tissues. In conclusion, central and peripheral lymphoid tissues in the mouse show different sequences of activation of clock gene expression compared to peripheral blood. These differences may underlie the compartmental pattern of web functioning in the immune system.

A method to evaluate dynamics and periodicity of hormone secretion.

Spontaneous hormone secretory dynamics include tonic and pulsatile components and a number of periodic processes. Circadian variations are usually found for melatonin, TSH and GH, with peak secretions at night, and in cortisol secretion, which peaks in the morning. Free thyroxine (FT4) and insulin-like growth factor (IGF)1 levels do not always change with circadian rhythmicity or show only minor fluctuations. Fractional variations explore the dynamics of secretion related to time intervals, and the rate of change in serum levels represents a signal for the receptorial system and the target organ. We evaluated time-related variations and change dynamics for melatonin, cortisol, TSH, FT4, GH and IGF1 levels in blood samples obtained every 4 h for 24 h from eleven healthy males, ages 35-53 years (mean ∓ SE 43.6 ± 1.7). Nyctohemeral (i.e., day-night) patterns of hormone secretion levels and the fractional rate of variation between consecutive 4-hourly time-qualified hormone serum levels (calculated as percent change from time 1 to time 2) were evaluated for circadian periodicity using a 24 and 12-h cosine model. A circadian rhythm was validated for serum level changes in cortisol with peaks of the 24-h cosine model at 07:48 h, and melatonin, TSH and GH, with phases at 01:35 h, 23:32 h, and 00:00 h, respectively. A weak, but significant, 12-h periodicity was found for FT4 serum levels, with minor peaks in the morning (10:00 h) and evening (22:00 h), and for IGF1, with minor peaks in the morning (07:40 h) and evening (19:40 h). Circadian rhythmicity was found in the 4-hourly fractional variations with phases of increase or surge at 02:00 h for cortisol, 22:29 h for melatonin, 05:14 h for FT4, and 21:19 h for GH. A significant 12-h periodicity was found for the 4-hourly fractional variations of TSH with two peaks in the morning (decrease or drop at 04:42 h) and afternoon (surge at 16:28 h), whereas IGF1 fractional variation changes did not show a significant rhythmic pattern. In conclusion, the calculation of the time-qualified fractional rate of variation allows evaluation of the dynamics of secretion and the specification of the timepoint(s) of maximal change of secretion, not only for hormones whose secretion is characterized by a circadian pattern of variation, but also for hormones that show no circadian or only weak ultradian (12 h) variations (i.e., FT4).

A timetable of 24-hour patterns for human lymphocyte subpopulations.

Specific lymphocyte cell surface molecules involved in antigen recognition and cell activation present different circadian patterns, with peaks and troughs reflecting a specific time-related compartment of immune cell function. In order to study the dynamics of variation in expression of cytotoxic lymphocyte cell surface molecules that trigger immune responses, several lymphocyte cell surface clusters of differentiation (CD) and antigen receptors, analyses were performed on blood samples collected every 4 h for 24 h from eleven clinically-healthy men. Assays for serum melatonin (peaking at night) and cortisol (peaking near awakening) confirmed 24-h synchronization of the subjects to the light-dark schedule. A significant (p≤0.05) circadian rhythm could be demonstrated for six of the 10 lymphocyte subpopulations, with midday peaks for CD8+dim (T cytotoxic cells, 11:15 h), gammadeltaTCR (gamma-delta T cell receptor-expressing cells, 11:33 h), CD8+ (T suppressor/cytotoxic cells, 12:08 h), and for CD16+ (natural killer cells, 12:59 h), and peaks during the night for CD4+ (T helper/inducer cells, 01:23 h) and CD3+ (total T cells, 02:58 h). A borderline significant rhythm (p = 0.056) was also observed for CD20+ (total B cells), with a peak late in the evening (23:06 h). Acrophases for 3 subsets, CD8+bright (T suppressor cells, 15:22 h), HLA-DR+ (B cells and activated T cells, 23:06 h) and CD25+ (activated T lymphocytes with expression of the alpha chain of IL2 receptor, 23:35 h), where a 24-h rhythm could not be definitively determined, nevertheless provide information on the location of their highest values and possible physiological significance. Thus, specific lymphocyte surface molecules present distinctly-timed profiles of nyctohemeral changes that indicate a temporal (i.e., circadian) organization of cellular immune function, which is most likely of physiological significance in triggering and regulating immune responses. Such a molecular cytotoxic timetable can potentially serve as a guide to sampling during experimental, diagnostic, therapeutic and/or other medical procedures.

Heart rate response to a standardized walking exercise in the Arctic circumpolar region in morning vs. evening during the polar night and midnight sun.

AIM: Awareness of daytime and/or seasonal variation in performance and exercise efficiency can be important for athletes and coaches in order to suitably plan training sessions and avoid over-training. The study goal was to evaluate and compare walking-speed and time-related heart rate (HR) responses to a walking task at two times of day and year. METHODS: Five healthy females (age 21-35 years) performed 9 km outdoor walking at 09:00h and 18:00h on 4 consecutive days in a period without sunlight (January) and with continuous daylight (May). Walking speed, average-heart rate (HR) and peak-HR (as %HRmax) were compared across all exercise sessions. RESULTS: In January the subjects achieved a higher peak-HR when they trained in the evening vs. morning, while average-HR and walking speed were not modified significantly. In May they achieved a higher peak-HR and kept a higher average-HR when they trained in the morning, under the same walking speed. In both training-times carried out in May, average-HR and peak-HR were lower compared with January, while the walking speed was unvaried. CONCLUSION: A lower exercise average and peak HR, that could potentially be a favourable condition for exercise conditioning, was observed at both daily test times in May vs. January, with overall lowest HR observed in May when exercise occurred at 18:00 h. These findings support the presence of both seasonal and time of day effects on HR responses to a standardized exercise.

Estrous influence on surgical cure of a mouse breast cancer.

We have studied the effect of estrous stage, as reflected by vaginal cellularity, at the time of surgical resection of an estrogen receptor-bearing mammary adenocarcinoma upon the metastatic potential of that tumor in the C3HeB/FeJ mouse. Presence of the tumor prolonged the length of the estrous cycle by approximately 25% and removal of the tumor returned the cycle to its usual duration. Neither estrous stage at tumor implant nor size of tumor at resection (within a small range) had significant independent effects upon differences observed in the incidence of subsequent pulmonary metastases. However, estrous stage at time of surgical removal of the tumor, as reflected by cell types in vaginal smear, markedly affected whether or not metastases ultimately appeared. Because the estrous cycle in mice, comparable to the human menstrual cycle, reflects high-amplitude, rhythmic changes in hormone concentrations, it may be that the hormonal status of a women at the time of tumor resection is an important determinant of whether or not that breast cancer ultimately metastasizes.

Expression of clock genes Per1 and Bmal1 in total leukocytes in health and Parkinson's disease.

BACKGROUND: There is a growing number of clinical studies that revealed a variety of behavioral and physiological desynchronies in patients with Parkinson's disease (PD). However, these desynchronies have not been defined at the molecular level. METHODS: Using real-time RT-PCR assay, we analyzed the expression profiles of two principle clock genes, PER1 and BMAL1, in total leukocytes for 12 h during the evening, overnight and morning in subjects with PD and age/sex-matched healthy controls. RESULTS: A difference in the expression pattern of BMAL1 but not PER1 was apparent during the dark span, where the relative abundance of BMAL1 was significantly lower in PD patients versus control subjects at 21:00, 00:00 and 06:00 h. Furthermore, expression levels of BMAL1 in PD patients correlated with their United Parkinson's Disease Rating Scale score at 06:00, 09:00 h, and with Pittsburgh Sleep Quality Index score at 06:00 h. CONCLUSION: These results suggest that a peripheral molecular clock, as reflected in the dampened expression of the clock genes BMAL1 in total leukocytes, is altered in PD patients. In addition, the relative BMAL1 levels correlate positively with PD severity, which could provide a molecular basis to help monitor disease progression and response to investigational drugs.

BLOOD PRESSURE, HEART RATE AND MELATONIN CYCLES SYNCHRONIZATION WITH THE SEASON, EARTH MAGNETISM AND SOLAR FLARES.

Three spectral components with periods of about (~) 0.41, ~0.5 and ~1.0 year had been found with serially independent sampling in human circulating melatonin. The time series consisted of around-the-clock samples collected for 24 hours at 4-hour intervals from different patients over several years. Some of these components had been found to be circadian stage-dependent, the daytime measurements following mostly a circannual variation, whereas a half-year characterized the nighttime samples. The latter were incorporated into a circasemiannual map. The relative brevity of the series prevented a check for the coexistence of all three spectral components, even if each component seemed to have a raison d'être. In time series of transdisciplinary data, a 1.00-year synchronized component is interpreted as representing the seasons. The half-year may qualify the circannual waveform, but it is also a signature of geomagnetics. An ~0.41-year (~5-month) component is the signature of solar flares. It has been called a cis-half-year (cis = on this side of a half-year) and may be detected only intermittently. Charles L. Wolff predicted the existence, among others, of ~0.42- and ~0.56-year components as beat periods of rotations at different solar latitudes.The multiple components characterizing circulating melatonin could also be found in a (to our knowledge unique) data set of a clinically healthy scientist (RBS). Herein, we focus on vascular data self-measured by RBS as he aged from ~20 to ~60 years. A multi-component model consisting of cosine curves with periods of 0.41, 0.50 and 1.00 year was fitted to weekly means of systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) collected ~5 times a day over 39 years by RBS. All three components can coexist for a while, although all of them are nonstationary in their characteristics and come and go by the criterion of statistical significance.Intermittently, BP and HR are synchronized selectively with one or the other aspect of RBS' physical environment, namely the seasons (at ~1.0 year), earth magnetism (at ~0.5 year) and/or solar flares (at ~0.42 year). Cosmic-biotic transfer of information, albeit hardly of energy (the biospheric amplitudes are very small) may be mediated in this set of frequency windows. As found earlier, RBS' circulation is also frequency-trapped environmentally in multidecadal windows, HR being locked into the transtridecadal Brückner, or rather Brückner-Egeson-Lockyer, BEL sunspot and terrestrial weather cycle, while his BP follows Hale's didecadal cycle in the changing polarity of sunspots.The ~0.41-year HR cycle may be associated with changes in solar flares, the cis-half-year amplitude of HR showing a cross-correlation coefficient of 0.79 with the total solar flare index (from both solar hemispheres) at a lag of ~3.2 years. The superposed time courses of these two variables indicate the presence of a shared Horrebow-Arago-Schwabe sunspot cycle of ~11 years, the cis-half-year in HR being more prominent after the total solar flare index reaches its ~11-year peak. Differences in the time-varying behavior of BP vs. HR are also described.

Increased tolerance of leukemic mice to arabinosyl cytosine with schedule adjusted to circadian system.

Mice (BDF(1)) inoculated with L1210 leukemia survive for a statistically significantly longer span when four courses of arabinosyl cytosine are administered at 4-day intervals-not in courses consisting of eight equal doses at 3-hour intervals, but in sinusoidally increasing and decreasing 24-hour courses, the largest amount being given at previously mapped circadian and circannual times of peak host resistance to the drug. This finding relates to the many therapeutic situations involving rhythmic, and thus predictable, cycles in the host's tolerance of undesired effects from the agent used.

Relationships between 24h observations in intraocular pressure vs blood pressure, heart rate, nitric oxide and age in the medical chronobiology aging project.

OBJECTIVE: To evaluate associations between intraocular pressure (IOP) and blood pressure (BP), heart rate (HR), serum nitric oxide (NO), diurnal variations, diabetes and aging in data collected during 24h studies of men conducted over 34y. MATERIALS AND METHODS: As part of the Medical Chronobiology Aging Project, male Army veterans, ages 22 to 81y, without a history of eye disease, were studied around-the-clock in May 1969 (n = 13), 1979 (n = 11), 1988 (n = 11), 1993 (n = 11), 1998 (n =12) and 2003 (n = 10). Measurements of IOP (R & L eyes, supine position), BP and HR (sitting position), and collection of blood were obtained every 3h (8 readings/24h) from 19:00h to 16:00h the next day. Individual time series were analyzed for circadian characteristics by the least-squares fit of a 24& 12h cosine. After normalizing all data to percent of mean to reduce inter-subject variability in levels, grouped data were analyzed for time-effect by ANOVA and for circadian rhythm by multiple component (24h&12h) cosine fitting. Individual 24h averages were analyzed by simple and multiple regression for relationships between IOP and systemic variables, diabetic status and age. RESULTS: Over the 34y study span, 22 men provided sixty-three 24h profiles for IOP & HR, 61 for BP, and 21 for NO. Using all normalized data, a significant circadian rhythm was found for each variable at p <0.001. Circadian peaks (orthophases) are located in the late morning for IOP-R (10:20h) and IOP-L (10:52h), and in the evening for HR (18:52h), NO (20:00h), SBP (20:40h) and DBP (21:44h). An out-of-phase relationship of about 10h is noted on a group basis between IOP vs BP, HR and NO. The locations of individual circadian peaks for IOP-R were found around the clock, but with a significant predominance between 10:00 and 16:00h (day type), and 04:00-10:00h (morning type). In contrast, BP, HR and NO showed a significant clustering of evening type or night type peaks. The overall mean IOP for the right eye was slightly, but not significantly, higher than the left eye (17.60+/-0.21 vs 17.34+/-0.18 mmHg; p = 0.385), with a strong positive correlation between both eyes (R = 0.952, p <0.0001). IOP showed a significant positive correlation with SBP (R = 0.49, p <0.001), diabetic status (R = 0.47, p <0.001), age (R = 0.32, p = 0.011), and HR (R = 0.28, p = 0.031). A multiple regression using SBP, DBP, HR, age and diabetic status (5 men became diabetic over the 34y study span) as independent variables resulted in SBP being the strongest predictor of IOP (p = 0.0001), followed by DBP (p = 0.0103). After adjustment for BP, independent effects of age (p = 0.187), HR (p = 0.789) and diabetic status (p = 0.153) were eliminated from the prediction equation. CONCLUSIONS: The results of these studies reveal significant circadian variations in IOP, BP, HR and NO, with peak levels, on average, near noon for IOP and in the evening for BP, HR and NO. An increase in SBP was associated with an increase in IOP. While SBP and DBP are significant predictors of IOP levels, single measurements during regular clinic hours may not reveal the full functional relationship between the variables measured in our studies. Therefore, circadian information on total 24h patterns may contribute to the reliability of diagnosis and guide proper individualized timing of optimal patient management (e.g., for glaucoma, hypertension, diabetes, among other conditions).

Control of a murine plasmacytoma with doxorubicin-cisplatin: dependence on circadian stage of treatment.

In anticipation of the development of clinical chronotherapy and in order to pick clinical test times for doxorubicin and cisplatin trials, two large studies were performed on rats bearing a transplanted plasmacytoma. The circadian timing of each of two anticancer drugs given at precisely equal dose intensities was expected to improve therapeutic benefit over conventionally given (time-unqualified) treatment. In each chronotherapeutic study, maximal benefit and minimal toxic effects were found when cisplatin was administered in the middle to latter part of the daily activity (dark) span, while doxorubicin was administered near the end of the daily resting (light) span for these nocturnally active rodents living on a 12-hour-12-hour or 8-hour-16-hour light-dark schedule. This was true whether doxorubicin or cisplatin was given first and whether there was a lag of only a few hours or a few days between the administration of these two agents.

Natural killer cell activity: age, estrous- and circadian-stage dependence and inverse correlation with metastatic potential.

The timing within the estrous cycle of surgical removal of a transplanted murine mammary tumor profoundly influences the frequency of pulmonary metastases. We investigated the potential role of the immune response in this phenomenon by measuring splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production in syngeneic tumor-free mice of two age groups at each of two circadian times and in each of four estrous stages. Estrous stage was determined by assessment of vaginal smear cellularity immediately prior to killing and spleen harvest. In a single-cell splenocyte preparation, NK cytotoxicity against a standard tumor cell target was assessed using a radiolabeled chromium release assay while IL-2 activity was determined in a bioassay utilizing the IL-2-dependent CTLL-2 cell line. Mice from the younger group were found to have eight-fold higher NK activity and 35% greater IL-2 production. After normalization of NK and IL-2 values for age, a highly statistically significant difference in NK activity was found among the four estrous and between the two circadian stages of sacrifice. NK activity was greater during the daily resting span across every estrous stage. IL-2 values were highest in diestrus and proestrus when sampled in the light span and in estrus-metestrus when sampled in the dark. The stages within the fertility cycle associated with lowest metastatic potential (proestrus/estrus) correspond precisely with those of highest splenocyte NK activity. These results indicate that an important component of the cellular immune response varies rhythmically both during the fertility and circadian cycles of the host. The rhythmic changes in NK activity may be in part responsible for the similarly rhythmic frequency of postsurgical metastatic dissemination.

Circadian distribution of iron and ferritin in serum of healthy and type 2 diabetic males.

AIM: We examined the circulating levels of iron and ferritin in serum of seven healthy and three insulin non-dependent diabetic (Type 2) males in order to compare their circadian characteristics. METHODS: Blood samples were collected every 3h over a 24h period and were analyzed for serum iron and ferritin. RESULTS: The mean Fe level was significantly higher in healthy than in diabetic subjects: 80.0 +/- 3.3 vs. 63.0 +/- 3.7 microg/dL. The ferritin level was significantly lower in healthy than in diabetic men: 79.8 +/- 4.7 vs. 186.3 +/- 110.5 microg/L. A significant (p < 0.001) time-effect was found by ANOVA and circadian rhythm was detected at p < 0.001 in all data sets when a 24h cosine was fitted to the normalized data. Acrophases were located in mid to late morning for Fe (11:30, vs. 09:22h) and for ferritin (11:10 vs. 11:46h). DISCUSSION: We concluded that there is significant circadian variation in both serum Fe and ferritin, with predictable peaks in the mid to late morning.

DNA synthesis and ploidy in non-Hodgkin's lymphomas demonstrate intrapatient variation depending on circadian stage of cell sampling.

Significant circadian cell cycle variations with a maximal number of cells in S-phase during the night have been found in a series of 24 patients (18 men and 6 women) with histologically established non-Hodgkin's lymphomas. Pathological lymph nodes of a total of 26 patients were punctured and aspirated by fine needle technique every 4 h during a single 24-h time span. Twenty-four patients (92.3%) had Stage III or IV disease. Twelve patients (46.1%) had low grade, 10 patients (38.5%) had intermediate grade, and 4 patients (15.4%) had high grade lymphomas according to the Working Formulation. The samples were analyzed by flow cytometry, and DNA synthesis (S-phase) and ploidy were determined according to circadian stage. The individual mean 24-h S-phase varied from 2.2 +/- 1.2% (mean +/- SD) to 24.0 +/- 3.3%. Within the group of patients with low grade lymphomas, a wide range in mean S-phase from 2.4 +/- 1.2% to 9.2 +/- 2.8% was observed. The percentage variation within each patient between the lowest and highest S-phase as compared to the lowest value (range of change) during the 24-h time span varied from 21 to 353%, with a mean range of change of 128 +/- 19%. When each individual S-phase series was converted to percent of mean and combined for analysis by one-way analysis of variance to test for time-effect across 2 12-h time spans (8 p.m.-8 a.m. versus 8 a.m.-8 p.m.), S-phase variation according to circadian stage was found to be statistically significant (P < 0.004), with higher values found in the 8 p.m.-8 a.m. time span. By single cosinor analysis, S-phase yielded a near significant P value of 0.069 for the least-squares fit of a 24-h cosine to all data as percent of mean, with the acrophase found to be near midnight (0.05 h). For those patients with low and intermediate grade lymphomas and with mean S-phase values < 10.0%, we found that mean S-phase was higher during winter (5.8 +/- 0.4%) than during spring (3.8 +/- 0.3%) or during fall (3.6 +/- 0.3%) (P < 0.001, analysis of variance). Twenty-one of the 26 patients (80.8%) had an aneuploid, hypodiploid, or near diploid population in one or several of the repeated samples. For the whole series, the DNA indices for the aneuploid populations varied from 1.09 to 1.96, the median DNA index being 1.20.(ABSTRACT TRUNCATED AT 400 WORDS)

CIRCANNUAL VARIATION IN HUMAN DIASTOLIC BLOOD PRESSURE DURING CONSECUTIVE SOLAR CYCLES.

Putative circadecadal modulations of a circannual variation in diastolic blood pressure are explored in a still accumulating 35 year record of self-measurements by a clinically healthy man. Analyses of monthly means by gliding spectra, one-way analysis of variance (ANOVA), and cosinor were carried out after removing data collected during travel across time zones or during illness. An about yearly change in diastolic blood pressure may or may not be detected with statistical significance by cosinor or ANOVA, apparently as a function of solar cycle number and/or stage. It appears to be, however, 1 year synchronized in the entire span analysed as a whole. A given variable such as diastolic blood pressure may be characterized by multifrequency rhythms that may intermodulate, so that findings in different stages of cycles with the lowest (e.g., circadecadal) frequency mapped may determine different outcomes in cycles with higher frequencies, such as circannuals.

Circannual and menstrual rhythm characteristics in manic episodes and body temperature.

Most reports in the literature deal with groups when summarizing the timing of affective disorders along the scale of the year and the menstrual cycle. In order to look for any regularity in timing of manic episodes in a single individual along these two time scales, a woman with a history of mania only, caused by schizoaffective disorder and on maintenance therapy with thioridazine hydrochloride self-measured basal body temperature daily and recorded onset and duration of manic episodes for 11 years. Statistically significant rhythms were found in body temperature with periods equal to the menstrual cycle and the year, with acrophase (highest values) during the luteal phase and winter, respectively. The timing of 11 manic episodes was not random but occurred during distinct portions of the menstrual cycle and the year. Most manic days occurred near menstruation or during the follicular phase of the menstrual cycle (up to ovulation) and between December and May (winter-spring). A temporal schedule for psychopharmacological treatment designed from individualized, longitudinal records that adjusts daily dosages according to both time of year and stage of menstrual cycle might alleviate or minimize the occurrence, magnitude and/or duration of mania and possibly other affective disorders that are found to be associated with underlying biological periodicities.

Weekly and yearly rhythms in plasma fibrinogen in hospitalized male military veterans.

The variation in plasma fibrinogen level demonstrating prominent circaseptan and circannual cycles is clinically relevant. There is a correlation between increasing level of fibrinogen and other hemostatic factors and risk of myocardial infarction and sudden death. The circaseptan and circannual cycles in fibrinogen concentration described in this study may help to explain further the variation in frequency of coronary events. Furthermore, the recent demonstration of a circadian pattern in the efficacy of tissue plasminogen activator, with peak efficacy occurring at 2000 hours--10 hours after the peak incidence of myocardial infarction--implies that further patterns to coronary artery syndromes may be predicted and the treatment efficacy may rely on demonstrated circaseptan and circannual cycles of these events.

Splenocyte natural killer cell activity and metastatic potential are inversely dependent on estrous stage.

We have previously shown that the timing of surgical removal of an estrogen-receptor-bearing mammary adenocarcinoma within the estrous cycle of the female C3HeB/FeJ mouse profoundly influences the frequency of subsequent tumor cell metastasis. In order to investigate the role of the immune response in this phenomenon, we measured splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production in 80 female cycling mice, 16 to 18 weeks old, assigned to one of four estrous stages as determined by relative quantity of vaginal cellularity; proestrus, estrus, metestrus, and diestrus. After prolonged synchronization on 12-hours-on, 12-hours-off light-dark circadian schedules, daily vaginal smears were obtained for 2 weeks to characterize estrous cycling. On the day the animals were killed, vaginal smears were performed and single-cell suspensions were prepared from the harvested spleens. Direct cytotoxicity of spleen cells against the YAC tumor target was assessed immediately in a 3 1/2 hour 51Cr release assay and expressed as NK activity in lytic units (LU 20%). IL-2 production was determined in a bioassay with the IL-2-dependent CTLL-2 cell line. Significant differences in NK activity among estrous stages mimicking the variation found in frequency of surgical cure from mammary adenocarcinoma were observed (p = 0.035; one-way analysis of variance), with the time of lowest metastatic potential corresponding precisely with the time of highest splenocyte NK activity. These both occurred during the proestrus and estrus stages, characterized by high fertility, ovulation, and peak FSH, LH, and estrogen concentrations. In addition, NK activity was found to correlate significantly with IL-2 production (r = 0.4, p less than 0.0005). These results indicate that important components of the cellular immune response to cancer vary rhythmically with hormonal changes in the host and may represent one of the factors affecting the delicate balance between host and tumor that alters the frequency of postsurgical metastatic dissemination.

Near 10-year and longer periods modulate circadians: intersecting anti-aging and chronoastrobiological research.

Biological cycles with relatively long and some unusual periods in the range of the half-week, the half-year, years, or decades are being discovered. Their prior neglect constituted a confounder in aging and much other research, which then"flew blind" concerning the uncertainties associated with these cycles when they are not assessed. The resolution of more about 10-year and other cycles, some reported herein, replaces the admission of complete unpredictability, implied by using the label "secularity." Heretofore unaccounted-for variability becomes predictable insofar as it proves to be rhythmic and is mapped systematically to serve as a battery of useful reference values. About 10-year cycles in urinary 17-ketosteroid excretion and in heart rate and its variability, among others, are aligned with cycles of similar length in mortality from myocardial infarction. Associations accumulate between cycles of natural physical time structures, chronomes such as the 10.5-year (circadecennian) Schwabe and the 21-year (circavigintunennian) Hale cycles of solar activity, and chronomes in biota. There are about 50-year (circasemicentennian) cycles in mortality from stroke in Minnesota and in the Czech Republic and also in human morphology at birth, the latter result reducing the likelihood that these cycles are purely human made. Associations among large populations warrant long-term systematic coordinated sampling of natural physical and biological variables of interest for the design of countermeasures against already documented elevated risks of stroke, myocardial infarction, and other catastrophic diseases, notably in elderly adults. New findings will be introduced against the background of the documented value of mapping rhythms in medicine and gerontology. In both these fields, rhythms promise the seeming paradox of better care for less.

Circadian relationships between circulating atrial natriuretic peptides and serum calcium and phosphate in healthy humans.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids (aa) 1 to 30, 31 to 67, and 99 to 126, respectively, of the 126-aa ANF prohormone circulate in humans. Among the biologic properties of these peptides is the ability of ANF to decrease intracellular calcium concentrations. To determine if atrial natriuretic peptides are directly related to serum calcium and/or phosphate in healthy normocalcemic humans, we examined 21 24-hour profiles of VSDL, LANP, ANF, and serum calcium and phosphate in 14 healthy humans. VSDL, LANP, and ANF each had significant (P < .001) circadian rhythms, with peak concentrations late during sleep (at 4:00 AM) being nearly twice the concentrations in the afternoon and evening. Serum calcium and phosphate also had significant circadian rhythms (P < .001) with troughs nearly opposite to those of the atrial natriuretic peptides, suggesting that atrial peptides may be important in the modulation of the circadian rhythms of calcium and phosphate. The nearly identical circadian rhythms of the atrial natriuretic peptides and of parathyroid hormone (PTH) reported by others, along with evidence that PTH may increase atrial peptide release, suggest that some of the effects attributed to PTH may be mediated by atrial natriuretic peptides.