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.

Pretranslational regulation of extracellular matrix macromolecules and collagenase expression in fibroblasts by mechanical forces.

In vivo, the extracellular matrix modulates the phenotype of the connective tissue cells both through its biochemical composition and the transfer of mechanical information. In this study, the mechanical effect was investigated in collagen gels populated by skin fibroblasts maintained under tension (bound lattices (BL)) compared with free retracting lattices (FL) and monolayer on plastic. The overall proteins and collagen synthesis of human skin fibroblasts, investigated by isotopic labeling, were decreased respectively by a factor of about 20 and 40 in FL compared with monolayers and increased by a factor of 4 and 6 in BL versus FL. As assayed by the degradation of [3H]collagen type I by trypsin-activated medium conditioned by fibroblasts under the three models of culture, collagenase activity was inversely regulated and increased in lattices when compared with monolayer culture. It was four times higher in FL than in BL. The steady-state level of mRNA coding for procollagen types I, III, and VI polypeptides, fibronectin, elastin, beta-actin, and procollagenase was determined by cDNA hybridization. The mRNA coding for beta-actin as well as for the various extracellular matrix macromolecules were increased in BL when compared with FL while the level of procollagenase mRNA was lower. These data demonstrate the existence of a modulation of the function of the fibroblasts performed by mechanical forces. This regulation operates, at least in part, at a pretranslational level.

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.

[Not Available].

Synopsis Several methods exist for measuring cutaneous relief. Profilometry allows the measurement of the profile of a skin-positive araldite replica. Image analysis detects and measures shadows behind the crests created by glazing lighting on a negative silicone skin replica. We have studied the correlation between both methods for twenty-nine crow's feet replicas. The area explored by image analysis is a circle of fifteen millimeters diameter. The areas explored by profilometry are, on one hand, ten scans 9500 mum long at intervals of 60 mum, i.e., 5.13 mm(2) (D 60 mum), and on the other hand ten scans of the same length at intervals of 900 mum, i.e., 76.95 mm(2) (D 900 mum). All parameters of peak height and surface were correlated. The best correlations were obtained between image analysis and profilometry for D 900 mum. In this case the P parameter (wrinkles depth measured by image analysis) was influenced for 46% by surface S under the peaks and for 33.5% by the peak height H measured by profilometry. In the same way the coefficient of developed skin surface CDSS was influenced for 45% by H and for 44% by S. The field of analysis common to both methods was found to be middle wrinkles with depth between 45 and 100 mum.