Analysis of circadian and ultradian rhythms of skin surface properties of face and forearm of healthy women.

Biologic rhythms of cells and organisms are well documented and have been extensively studied at the physiologic and molecular levels. For the skin, many circadian changes have been investigated but few systematic studies comparing skin at different body sites have been reported. In this study we investigated facial and forearm skin circadian rhythms in eight healthy Caucasian women. Noninvasive methods were used to assess skin capacitance, sebum excretion, skin temperature, transepidermal water loss, and skin surface pH on fixed sites of the face and the volar forearm during a 48 h span under standardized environmental conditions. Using the cosinor or ANOVA methods, circadian rhythms could be detected for sebum excretion (face), transepidermal water loss (face and forearm), skin temperature (forearm), pH (face), and capacitance (forearm). No circadian rhythmicity was found for the other biophysical parameters. In addition to the 24 h rhythm component, rhythms with periods of 8 h were found for sebum excretion, of 8 and 12 h for transepidermal water loss (face and forearm), and of 12 h for skin temperature (forearm). Our study confirms that rhythms of skin surface parameters are readily measurable and that these rhythms differ between different sites. Furthermore, we demonstrate for the first time that, for transepidermal water loss (face and forearm), sebum excretion, and skin temperature (forearm), in addition to circadian rhythms, ultradian and/or component rhythms can be detected.

Role of school schedule, age, and parental socioeconomic status on sleep duration and sleepiness of Parisian children.

The aim of the study was to assess the duration and quality of sleep of prepubertal (Tanner Scale level 1) physically and mentally healthy children as a function of school schedule (4 versus 4.5 days per week), age and grade (median age of 9.5 years for 4th grade versus median age of 10.5 years for 5th grade), school district (wealthy versus nonwealthy) in Paris, France, and parental socioeconomic status (high, medium, or low). We studied 51 girl and 44 boy volunteer pupils with written parental consent. The study lasted 2 weeks during the month of March. During the first study week, the children attended school 4.5 days, and during the second week, they attended school only 4 days without difference in the length of the school day. A sleep log was used to ascertain time of lights off for sleep and lights on at awakening, nighttime sleep duration, and self-rated sleep quality. A visual analog scale (VAS) was also used by pupils to self-rate the level of perceived sleepiness at four specific times of the school day. Conventional statistical methods (e.g., t and chi2 tests) were used to examine differences in mean values. Sleep duration, self-rated sleepiness, and subjective sleep quality were comparable (P > .05) by gender, school schedule, school district, and parental socioeconomic status. Overall, the sleep of this sample of Parisian children around 10 years of age was rather stable in its duration and timing, suggesting flexibility to adjust to the different school schedules.

Variability in the period of the blood pressure circadian rhythm in human beings.

In studies and assessments of human beings done in natural settings, it is assumed that the period tau of circadian rhythms, including ones of systolic (SBP) and diastolic (DBP) blood pressure, is equal to 24 hours. To test this hypothesis, SBP and DBP rhythms were studied in 112 medication-free, non-hospitalized subjects (62 males, 47.1 + 2.0 years [x +/- SEM], and 50 females, 54.5 +/- 2.1 years) by 48 h ambulatory blood pressure monitoring (ABPM). Of these, 26 were hypertensive (diurnal SBP > 140 mmHg and diurnal DBP > 90 mmHg) and 86 normotensive. All subjects were synchronized by their habitual daytime activities from approximately 08:00 h to approximately 23:00 h +/- 1 h and by sleep at night. The BP was assessed at 15-minute intervals during a continuous 48h span using a Spacelabs model #90207 ABPM. The time series data of each subject were individually evaluated by power spectra analysis for the prominent tau of the SBP and DBP rhythms. The prominent tau differed from 24 hours in 22/112 subjects for SBP and in 16/112 subjects for DBP. Generally, in these individuals the tau was less than 24 hours. The occurrence of non-24 h tau's was more frequent in hypertensive than normotensive subjects; the difference between the groups in the distribution of the prominent tau's by class (tau = 24 h, tau = 12, 12 h > tau < 24 h, etc.) was statistically significant (chi 2 test = 19.1; p < 0.001). No difference in the distribution of tau's of blood pressure was detected according to the subject's age and gender. These findings suggest that ABPM done only for a duration of 24 h may be too short to characterize accurately the features of the day-night variation in human BP, including the precise period of its rhythm.

Circadian rhythm period in reaction time to light signals: difference between right- and left-hand side.

The study was designed to test the hypothesis that the prominent rhythm period tau of simple reaction time (SRT) and three-choice reaction time (CRT) to light signals may vary between the dominant (DH) and non-dominant (NDH) hand. Eleven healthy subjects, 8 males (16-74 years, including two left-handed) and 3 females (18-43 years), synchronized with a diurnal activity (approximately 07.00 h to approximately 23.00 h) and a nocturnal rest, volunteered for the study. A battery-powered ambulatory device was used to self-record SRT to a yellow light signal and CRT to yellow, green and red signals. Tests were performed 4-7 times/24 h during a 12- to 15-day span. Power spectra, ANOVA, cosinor, chi2 and correlation tests were used to individually analyze time series. Tau = 24 h in SRT rhythms of DH (8/11 cases) and NDH (6/11 cases) with chi2 = 3.5 and p > 0.05. In CRT rhythms, tau = 24 h for DH (8/11 cases) while tau = 8 h for NDH (7/11 cases), a difference which was statistically significant (chi2 = 9.4 with p < 0.02). Concordant results were obtained with other statistical tests leading to the conclusion that the rather complex cognitive task (CRT) and, to a certain extent, SRT of certain individuals, were associated with tau = 24 h for DH and tau = 8 h for NDH. These findings are in favor of the hypothesis that functional clocks are present in the human brain cortex, associated with the possible expression of rhythms with a prominent period differing from the right- and left-hand side.

Serum thymidine kinase levels are elevated and exhibit diurnal variations in patients with advanced ovarian cancer.

Deoxythymidine kinase (TK) is an enzyme involved in DNA synthesis whose serum activity reflects the proliferative activity of tumors and correlates with prognosis in various malignancies. In ovarian cancer, the value of s-TK has not been studied so far. Therefore the serum levels of TK were investigated in patients with advanced ovarian cancer. Because considerable diurnal fluctuations of s-TK levels were reported previously, repeated determinations were performed over a 48-h time span. Fourteen patients (mean age +/- S.D., 56.1 +/- 8.0 years) with advanced ovarian cancer and five healthy volunteers (30.2 +/- 3.5 years) were studied. Serial determinations of s-TK and serum CA 125 (s-CA 125) levels were performed over a 48-h time period. S-TK and s-CA 125 were elevated (> 4.7 U/l and > 35 U/ml) in 10 patients at least once over the 48-h period, respectively. Linear regression analysis showed a strong correlation between s-TK and s-CA 125. However, three patients with consistently normal s-CA 125 values (< or = 35 U/ml) had elevated s-TK levels, indicating that these two parameters may be independent in some patients. Both s-TK and s-CA 125 levels showed considerable diurnal changes over the 24-h period in individual patients, in marked contrast to normal subjects. Individual peak-trough differences ranged from 0.1-8.5 U/l or 5-268% for s-TK, and from 4-75 U/ml or 15-100% for s-CA 125. Peak-trough differences of s-TK > or = 100% were found in five patients. The circadian fluctuations of s-TK and CA 125 did not show a regular circadian pattern nor any temporal covariation. This study demonstrates for the first time that s-TK levels may be elevated in ovarian cancer. In some patients, s-TK levels may exhibit considerable, irregular diurnal fluctuations. Repeated determinations should therefore be performed in situations where this marker is relevant for patient monitoring.

Oral contraceptives alter circadian rhythm parameters of cortisol, melatonin, blood pressure, heart rate, skin blood flow, transepidermal water loss, and skin amino acids of healthy young women.

Sixteen healthy women users and nonusers of oral contraceptives (OC) volunteered to document a set of circadian rhythms. Nine were taking OC providing ethynyl estradiol (0.03-0.05 mg/24h, 21 days/month) combined with DL- or L-norgestrel or norethisterone. There was no group difference (p > 0.05) in median age (22 years), weight (57 kg), and height (162) cm). Data were obtained at fixed hours, 5 times/24h, during a 48-h span, in November. (Day activity from approximately 08:00 to approximately 23:00 h and night rest). Environmental conditions were controlled, using air-conditioned rooms of constant temperature (26 degrees +/- 0.5) and relative humidity 45% +/- 1. Both cosinor and ANOVA were used for statistical analyses. All circadian rhythms were validated with one exception: that of salivary melatonin was not detected in OC users. The 24h mean (M) exhibited group differences for certain variables: M was greater in OC than non-OC users for systolic blood pressure (p < 0.0001), heart rate (p < 0.01), skin blood flow (p < 0.04), and transepidermal water loss (p < 0.02). M was lower in OC than non-OC users in salivary cortisol (p < 0.04) and skin amino acids (p < 0.003). No group difference was detected in any other documented rhythms: diastolic blood pressure, grip strength of both hands, oral temperature, self-rated fatigue, and the skin variables of urea, lactate, triglycerides, and acid phosphatase activity.

PIP: In November in France, researchers compared data on 8 healthy women using combined oral contraceptives (OCs) containing ethinyl estradiol (0.03-0.05 mg/24 h, 21 days/month) and DL-norgestrel, L-norgestrel , or norethisterone with data on 8 healthy women not using OCs to assess circadian changes in a set of various variables. They obtained data from all subjects in the sitting position, both forearms lying horizontally on armchair supports, flexor surfaces up, at fixed clock hours (04:00, 09:00, 14:00, 19:00, 23:00 h) during a 48 hour span, beginning on Friday at 18:00 h and ending Sunday at 15:00 h. The data were obtained during the follicular/luteal phases only, and not during menses. The women maintained a social synchronization with a nonstrenuous diurnal activity from 07:00 to 23:00 h and a nocturnal rest. Environmental conditions were controlled (26 degrees Celsius and relative humidity of 45%). The 2 groups were similar in median age (22 years), weight (57 kg), and height (162 cm). The 24 hour mean was greater in OC users than nonusers for systolic blood pressure (104.4 vs. 101.1 mmHg; p 0.0001), heart rate (73 vs. 69.3 count/min; p 0.01), skin blood flow (295 vs. 271 arbitrary units; p 0.04), and transepidermal water loss (317 vs. 287 arbitrary units; p 0.02). It was lower in OC users than nonusers for salivary cortisol (30.7 vs. 39.3 mcg/dl; p 0.04) and skin amino acids (0.9 vs. 7.6 nmoles/sq cm; p 0.003). Even though the 24 hour mean for salivary melatonin and the peak time were similar for both groups, the peak time was only significant in nonusers (p 0.02), suggesting that OCs obliterated the circadian rhythm of melatonin. It has been suggested that OCs alter an individual's sensitivity to light and consequently the circadian rhythm of melatonin. Other documented rhythms (diastolic blood pressure, grip strength of both hands, oral temperature, self-rated fatigue, and the skin variables of urea, lactate, triglycerides, and acid phosphatase activity) were similar in both groups.

Circadian dosing time dependency in the forearm skin penetration of methyl and hexyl nicotinate.

The forearm skin penetration of hydrophilic methyl nicotinate (MN) and lipophilic hexyl nicotinate (HN) was assessed around the clock. The sixteen healthy women (median age: 22 years, weight: 57 kg and height: 162 cm) who volunteered for the study were synchronized with a diurnal activity from 07.00h (+/- 1h) to 23.00h (+/- 1h.30min) and a nocturnal rest before and during the 48h sojourn in air-conditioned rooms (26 degrees C +/- 0.5 degrees C). Both HN (0.5% ethanol solution) and MN (5% ethanol solution) have a vasodilative effect on dermal vessels. The lag time (LT) between the delivery of a fixed volume (10 microliters) of the agent at the skin surface and the beginning of the vasodilatation, detected with a laser-Doppler method, was used to quantify the penetration kinetics. Tests were performed every 4h, at fixed clock hours, over a span of a 40h. Two types of tests were done with each of the agents: fixed site (one site only) and shifted sites (10 different places). Both cosinor and ANOVA have been used for statistical analyses. The shortest LT (fastest penetration) was located around 04.00h. The longest LT (slowest penetration) occurred during the day with a single peak around 13.00h in three of the situations, or two peaks (HN with fixed site). A rather large rhythm amplitude (peak-to-trough difference larger than 50% of the 24h mean LT) was validated.

Day-night differences in effects of cosmetic treatments on facial skin. Effects on facial skin appearance.

Two groups of 24 healthy caucasian women, similar with regard to age classes (from 19 to 55) as well as fair and dark complexion of skin and hair, volunteered to use during a 14-day span a conventional facial cream (active placebo: AP) and thereafter, during a 21-day span Noctosome (Noctos). The latter is a new generation of liposome made with non-ionic lipids leading to microspheres which include glycopeptides in the aqueous compartment of the vesicle, alpha-tocopherol ester in the membrane-like structure and sphingo-ceramides at the surface of the microspheres. The aim of the study was to test the beneficial effects of Noctos (vsAP) with respectively morning (7-9-hr) and evening (21-23-hr) applications as facial ointments. Observed differences were validated using several statistical tests: ANOVA, cosinor, etc. Subjects were socially synchronized with a diurnal activity from 7 hr to 23 hr and a nocturnal rest. Each day, at fixed clock hours (7, 10, 20 and 23 hr), each subject used visual analogue scales to self-rate a set of variables characterizing facial aspects. Brilliance of complexion and texture of skin exhibited a circadian rhythm (peak time at 10 hr), both with AP and Noctos. The latter produces a beneficial effect with regard to reference values (AP). The evening application of Noctos is more efficient than the morning one. However, the magnitude of this beneficial effect is related both to age (greater for the age class 25-35 years than for younger and older subjects) and to skin complexion (greater for fair than dark complexioned subjects). Major beneficial effects of Noctos in the evening hours are related neither to fatigue nor to mood of the women since the respective circadian rhythms of these variables appear to vary independently from those of facial skin characteristics.

Circadian rhythms in circulating T lymphocyte subtypes and plasma testosterone, total and free cortisol in five healthy men.

Circadian variations of circulating T lymphocyte subtypes and their possible relations with those of endogenous cortisol or testosterone were investigated in five healthy young men. Venous blood (40 ml) was obtained every 4 h for 24 h from each subject in January, March, June, August and November. Leucocyte and differential counts were measured. Mononuclear cells were isolated on Ficoll-Paque gradient, and samples were incubated with OKT3, OKT4 or OKT8 monoclonal antibodies for characterizing all T, T helper and T suppressor-cytotoxic lymphocytes respectively. The proportion of labelled lymphocytes was determined under an epifluorescence microscope and the counts of circulating lymphocyte subsets (cells/mm3) computed. Total and free cortisol and testosterone were also determined in the corresponding plasma samples. Results from analysis of variance and cosinor indicated statistically significant differences (P less than 0.001) as a function of both individual subject and circadian sampling time for all variables. Circadian rhythms (with a period, tau = 24 h) were validated for total, T and T helper lymphocytes and for the T helper: T suppressor-cytotoxic ratio (P less than 0.001), with double amplitudes (2A, total extent of variation accounted for by the fitted cosine function) ranging from 25% up to 50% of the 24 h mean (M), and acrophases (phi, time of maximum) localized near 0100 h. A rhythm with tau = 12 h characterized circulating T suppressor-cytotoxic lymphocytes (P less than 0.001; 2A = 36% of M; phi = 0830 and 2030 h). Circadian rhythms were also found for plasma cortisol (either total or free) and testosterone (P less than 0.001). No correlation was found however between time-qualified data of these hormones and the immunological variables herein investigated (162 pairs of data) whether or not a 4 h or an 8 h lag time was considered to allow for hormonal actions to operate. This suggests that neither the circadian organization of the adrenal cortex nor that of the testis play a prominent role in the circadian time structure of the circulation of T lymphocytes.

Circadian changes in the pharmacokinetics of oral ketoprofen.

Several investigations which have taken treatment time into account have shown that the pharmacokinetic parameters, the therapeutic efficacy and even the toxicity of a large number of products may vary according to the administration schedule. The present study was carried out in order to evaluate any circadian changes in pharmacokinetic parameters of ketoprofen, a new non-steroidal anti-inflammatory drug (NSAID). This randomised crossover study consisted of a single oral dose of ketoprofen 100mg administered to 8 healthy male volunteers, mean age 27.2 years, at 07.00 hours, 13.00 hours, 19.00 hours or 01.00 hours in 4 study periods during the first 3 months of the year. The order of administration was randomised, with each subject acting as his own control. A total of 14 blood and 4 urine samples were taken over a 12-hour period. The peak plasma concentration was twice as high after drug administration at 07.00 hours (13.4 +/- 1 mg/L) than after other administration times (13.00 hours: 6.9 +/- 1; 19.00 hours: 7.2 +/- 0.7; 01.00 hours: 6.3 +/- 0.5 mg/L) [p less than 0.001]. The time to reach peak concentration was much longer after drug administration at 01.00 hours (135 +/- 16.7 min) than at 07.00 (73.1 +/- 14.1 min), 13.00 (75 +/- 16.5 min) or 19.00 hours (82.5 +/- 12.7 min) [p less than 0.05]. The lag time was significantly longer at 01.00 hours than at 13.00 hours (p less than 0.01). The absorption rate constant after treatment at 01.00 hours was less than at the other times of administration (p less than 0.05). The bodyweight-corrected area under the curve (AUC0-12) was greater after 07.00 hours than after 13.00 (p less than 0.01) or 19.00 hours (p less than 0.05) and greater after 01.00 hours than after 13.00 hours (p less than 0.05). The elimination half-life was significantly longer after administration at 01.00 hours than after 19.00 hours (p less than 0.05), while the total clearance was lowest at 07.00 hours. Cosinor analysis demonstrated statistically significant circadian rhythms for all pharmacokinetic parameters described above. The amount of ketoprofen eliminated in the urine was delayed, and was significantly greater after the administration at 01.00 hours than 07.00 hours or 19.00 hours (p less than 0.01). The relationship between absorption, diffusion and/or elimination mechanisms of the drug are discussed.

Circadian time dependence of murine tolerance for the alkylating agent peptichemio.

Since the extent of host toxicity of cytostatics is considerably affected by dosing time, a chronopharmacologic approach was undertaken for optimizing the therapeutic index of the alkylating agent, peptichemio (PTC). In 4 studies involving a total of 463 male B6D2F1 mice, a highly statistically significant circadian rhythm characterized murine tolerance for PTC (8 or 10 mg/kg/day i.v. X 3 days). Six circadian stages were explored (3, 7, 11, 15, 19 and 23 Hours After Light Onset--HALO). Day-40 survival rate varied between 20% (PTC at 3 HALO) and 55% (PTC at 15 HALO) (chi 2 = 16.7; P less than 0.01). In each study, body weight loss was maximal in mice injected with PTC at 3 HALO and minimal in those treated at 15 HALO (P less than 0.01). In a further study involving 96 male B6D2F1 mice, the toxicity of PTC on several target tissues (bone marrow, spleen, small bowel, colon, liver, kidney and lungs) was investigated by histology and leukocyte count as a function of drug dosing time. A circadian rhythm in the susceptibility of the bone marrow, the spleen and the intestinal tract was demonstrated. Optimal murine tolerance for PTC resulted from dosing it at 15 HALO, e.g. in the first half of the activity span.

Circadian and circahemidian rhythms in plasma prolactin of the ram: seasonal changes.

The existence of a circadian rhythm in plasma prolactin of the ram is controversial. Differences among authors can be related to both data sampling (e.g. interindividual changes, time of day, time of year, sampling interval among others) and statistical analyses. To test this hypothesis six adult "Préalpes du Sud" rams were studied individually during 72 hr in January (8 hr of light-16 hr of darkness), April (13L-11D), June (16L-8D) and September (13L-11D). Blood was sampled (vacutainer) from a jugular vein every hour, centrifuged and plasma samples stored at -20 degrees C until prolactin determinations (radioimmunoassay) were made. Individual time series were analysed according to three complementary methods: display of raw data (chronogram), best fitting cosine functions with different period tau (iterative cosinors) and power spectra. Seasonal changes in the 24 hr mean (peak time in June) were confirmed. A circahemidian rhythm (tau = 12 hr) and a circadian rhythm (tau = 24 hr) were validated, respectively in January and April while time series documented in June and September exhibited no rhythmic organization. It seems, therefore, that animals adjusted their rhythmic patterns of prolactin secretion to the increasing (January, April) rather than decreasing (June, September) photofraction (duration of the light span/24 hr).

Circannual and circa-hemiannual rhythms of basal and stimulated gastric secretion in conscious cats.

Conscious cats equipped with a gastric fistula and a denervated Heidenhain pouch were submitted to weekly measurements of the basal and pentagastrin-stimulated gastric secretion for 1 to 14 years. Rhythms of basal secretion were documented in 37 cats for the group studies, in 25 cats only for the individual studies which required at least whole year data. Twelve-month or 6-month rhythms were detected for each variable studied, i.e. volume, acid, pepsin, fucose and uronic acid outputs in the group studies, with peaks for volume, acid and pepsin in Winter, peaks for uronic acid in Spring and Fall indicating different rhythms for oxyntic, chief and mucous cells. Individual studies detected rhythms in 25% of the analyses, and demonstrated male and female and cat to cat differences. Spectral analysis in 3 cats confirmed the differences in the individual rhythms with prominent peaks differing from 365 days in 50% of the cases. Chronopharmacological responses to pentagastrin were documented for volume, acid and pepsin outputs in 5 male and 6 female cats. Group analysis detected a Winter acrophase for volume and acid secretion and a Summer acrophase for pepsin secretion. Analysis of the stimulated response data showed interindividual variation but a higher percentage of detection for rhythms, i.e. 38% for all variables and 50% for pepsin secretion. Different rhythms in acid and pepsin secretion documented in individual studies could provide the basis of a better understanding of the discrepancies reported in the literature concerning the seasonal incidence of peptic ulcer disease.

Cancer-associated alteration of circadian rhythms in carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) in humans.

A circadian rhythm of serum concentrations of two tumor markers (CEA and AFP) was demonstrated in individuals not suffering from cancer. These rhythms exhibited a diurnal peak with a nocturnal dip. They disappeared in cancer groups. However, in some cancer subjects, a circadian activity was still detectable, but with quite different characteristics (time of peak, amplitude) of rhythms when compared to controls. The importance of such findings is discussed with regard to the circadian kinetics of cancer cells, to time scheduled cancer treatments and to the detection of cancer.

[Circadian rhythms of the so-called inflammation proteins in healthy subjects]. / Rythmes circadiens des protéines dites de l'inflammation chez le sujet sain.

Circadian rhythms for the factors listed below were investigated in 14 subjects hospitalized in apparently good health: total proteins, albumin, pre-albumin, alpha-1-antitrypsin, orosomucoid, ceruloplasmin, C3, C-reactive protein, haptoglobin and transferrin. Seven venous blood samples were taken from each subject over a 24 hour period. A circadian rhythm was detected for the total proteins, prealbumin, alpha-1-antitrypsin, orosomucoid, ceruloplasmin and transferrin. The acrophases occurred at about 12 hour intervals and the authors research group are already investigating these rhythms for the "inflammation proteins" and the transport proteins in cancer and inflammatory processes.

Circadian rhythm in tolerance of mice for etoposide.

Etoposide (40 mg/kg/day X 3 days and 60 mg/kg/day X 3 days) was best tolerated by male B6D2F1 mice when given in the second half of the rest span of their sleep-wake circadian cycle. Such a time-qualified treatment resulted in increased long-term survival rate, highest peripheral leukocyte count at nadir, and lowest body weight loss, as compared to results from drug dosing in the activity span. Assuming that such results may be extrapolated to human beings, the treatment time of etoposide associated with an optimal tolerance would be located in the second half of the sleeping span (usually near 5.00 hrs).

Circadian rhythm in tolerance of mice for the new anthracycline analog 4'-O-tetrahydropyranyl-adriamycin (THP).

A statistically significant circadian rhythm in tolerance of 226 male B6D2F1 mice synchronized with LD 12:12 for 4'-O-tetrahydropyranyl-adriamycin (THP) was demonstrated. Four intravenous dosages (18, 25, 32 and 40 mg/kg) and six different dosing times (3, 7, 10, 14, 19 and 23 hr after light onset-HALO) were compared. Survival rate, body weight loss and leukopenia depended on both the dose and time of injection. The overall survival rate varied between 83% (light-rest span) and 56% (dark-activity span) (chi2 = 17; d.f. = 2; P less than 0.001). Maximal body weight loss occurred 4-5 days after drug injection. Total leukocyte counts were determined on these days. Both body weight loss and leukopenia were reduced by approximately 100% in those mice injected in their late rest span (7-10 HALO) as compared to those treated in the middle of their activity span (19 HALO). Circadian rhythms in day-60 survival rate, body weight loss and leukopenia were statistically validated by cosinor analysis, with estimated peak times (acrophases) occurring respectively at 7:30, 9:20 and 8:40 HALO. Minor cardiac lesions consisting of diffuse vacuolization and loss of muscular striation were observed in histologic sections from 3/32 hearts (16 controls, 16 treated). All three corresponded to THP given at 19 (2/2 mice) or 23 HALO (1/4 mice). Thus lethal, hematologic and possibly cardiac tolerance for THP were largely optimized by administering the drug to mice in their late span (7-10 HALO).

Circadian and/or circahemidian rhythms in nine lymphocyte-related variables from peripheral blood of healthy subjects.

Circadian variations were investigated for nine lymphocyte-related variables in the peripheral blood of healthy subjects. Monoclonal antibodies targeted at membrane immunoglobulins (anti-Ig, anti-kappa, anti-lambda) or differentiation antigens (anti-IA and OKT3) were used to characterize respectively mature B cells (SIg+, kappa +, lambda +), cells expressing HLA-DR antigen (IA+), and T cells (OKT3+). Blood (33 ml) was drawn every 4 hr for 24 hr starting at 8.30 hr, on seven occasions in five apparently healthy male volunteers, recumbent from 23.00 hr to 07.00 hr. Leukocyte and differential counts were measured. Mononuclear cells were isolated on Ficoll-Hypaque before being incubated with monoclonal antibodies. The proportion of fluorescent cells per 100 microscopically determined cells was multiplied by the number of circulating lymphocytes per milliliter of venous blood. Temporal variations were validated by both paired t-test and cosinor. Rhythms with a period (tau) identical to 24 hr were validated with statistical significance (p less than 0.05) for total lymphocytes, OKT3+ cells and OKT3+:SIg+ ratio, and suggested (0.05 less than or equal to p less than or equal to 0.10) for lambda + and (kappa + + lambda +) cells. Rhythms with tau identical to 12 hr were also found (p less than 0.05) for OKT3+, SIg+, kappa +, and IA+ cells as well as for the OKT3+:SIg+ and the kappa +:lambda + ratios. Validated rhythms exhibited a large amplitude, e.g., peak-through differences were 40% of the 24-hr mean. This circadian and circahemidian temporal structure of immunologic variables constitutes a time-qualified reference system for investigating immune regulations and a tool for optimizing both diagnostic criteria and effectiveness of immunotherapeutic attempts.

A histological assessment of the four-day subrenal capsule assay (SRCA).

A four-day subrenal capsule assay (SRCA) was developed, since fragments of human tumours implanted under the renal capsule of immunocompetent mice became rejected by the host within six days. The assay requires a histological assessment of both its exploitability and the extent of drug-induced anti-tumour lesions. 45 tumours from 43 patients with solid tumour were submitted to an SRCA in 1410 male B6D2F1 mice. After being biopsied each tumour was dissected by a pathologist, cut into 50 pieces (1.5 mm3), and one piece was implanted under the renal capsule of 35 mice; the mean tumour diameter was measured on day 0. The mice were randomized into groups of 6 to 10 animals each. On days 1, 2 and 3, the mice were treated with either placebo (control group) or with various anticancer agents. On day 4 the animals were sacrificed, the mean tumour diameter measured, the tumour bearing kidney fixed in Bouin's picroformol solution and processed for histological analysis after staining with hematein. Fragments of fresh explants of human tumours retained their proliferative and metabolic capacity: mitoses were observed as well as keratinizing cells in epidermoid carcinomas and melanin-producing cells in melanomas. Proliferation of tumour cells was seen along the renal capsule suggesting their affinity for connective tissue. Capillaries filled with mouse erythrocytes were also seen. No or minimal lymphocytic infiltration was found. Drug oncolytic effects ranged from minor cellular degeneration to almost complete necrosis and were documented by the scoring of histologic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)