In vivo method for evaluating sunscreen protection against high-energy visible light.

BACKGROUND: Overexposure to sunlight can have many harmful biological effects on the skin, leading to skin cancer and photoaging. As ultraviolet (UV) radiation has been identified as a cause of DNA damage and oxidative stress in the skin, the photoprotection provided by sunscreens is evaluated through their ability to filter UV light, using the sun protection factor (SPF). However, recent data have shown that high-energy visible (HEV) light can also cause biological skin damage. OBJECTIVES: To develop a new in vivo method for evaluating the protection provided by sunscreens across a broad range of wavelengths, including the HEV band, based on multispectral image analysis. METHODS: This study evaluated the absorption properties of six commercially available sunscreens (five SPF 50+ products containing organic UV filters, and one product containing the wide spectrum filter, phenylene bis-diphenyltriazine [TriAsorB™]) and of a control product containing no filter. Multispectral images were acquired from the skin on the forearms of healthy volunteers, before and after application of the test products. Images taken with LEDs emitting light at wavelengths ranging from UV to infrared were used to generate light reflectance maps for each product. The levels of absorbance of light in the UV and visible bands were then calculated. RESULTS: The product containing the wide spectrum filter exhibited significantly higher absorbance over the HEV band (380-450 nm) than the control product and the other commercial sunscreens. All the sunscreens tested showed the same level of absorbance at 365 nm (UVA). CONCLUSIONS: Multispectral imaging provides a simple and reliable in vivo method for assessing the real-world protection provided by sunscreens against all forms of photo-induced skin damage, including that induced by HEV radiation.

Protection against summer solar lentigo over-pigmentation with a SPF30 daily cream.

BACKGROUND/PURPOSE: The aim of this study was to measure lentigines' pigmentation over a long period of time and evaluate if summer over-pigmentation can be avoided by the use a SPF30 day skin cream. METHODS: Seventeen healthy female volunteers aged 50 and over and presenting lentigines participated in the study from spring to summer. Throughout the study, all subjects applied a SPF30 daily skin cream to only one hand. Color measurements of the target lesions were performed with a chromameter and with a color-calibrated camera. Target lesions were also imaged with in vivo reflectance confocal microscopy (RCM). A specific procedure for re-registering the images was developed to ensure that the same papillae were measured over time. RESULTS: Both color measurement methods, chromametry and color-calibrated camera, showed that lentigines treated over time with the SPF30 day skin cream were significantly lighter than the non-treated lentigines. The RCM images showed a decrease in the papillary contrast for the treated lentigines. CONCLUSION: This study shows that this over-pigmentation can be avoided using a SPF30 day skin cream. Moreover, we have demonstrated that very fine re-registration of the RCM images is possible and ensures a more robust analysis.

[Young women with atypical endometrial hyperplasia or endometrial adenocarcinoma stage I: will conservative treatment allow pregnancy? Results of a French multicentric survey]. / Hyperplasies atypiques et carcinomes de l'endomètre de stade I chez la femme jeune désirant une grossesse: le traitement conservateur est-il envisageable? Résultats d'une étude multicentrique française.

OBJECTIVES: To analyse the carcinological and obstetrical results of young women with atypical endometrial hyperplasia or endometrial adenocarcinoma, treated in a conservative way to allow pregnancy. PATIENTS AND METHODS: A retrospective analysis of 13 cases (5 adenocarcinomas and 8 atypical hyperplasias) followed in 8 French centers between 1997 and 2004. RESULTS: After 4.6 months of conservative treatment, there were no residual lesions in 61.5% of the cases. Progestatives seem to be the most effective treatment. Tumoral regression makes it possible to plan a pregnancy, with childbirth in 25% of the cases. In these frequently infertile patients, all the techniques of assisted reproduction can be used. Recurrences are not rare after hormonal treatment (37.5%), so, total hysterectomy is justified after delivery. DISCUSSION AND CONCLUSION: Conservative treatment for young women with atypical endometrial hyperplasia or endometrial adenocarcinoma stage I can be considered in some cases to enable pregnancy.

Relaxation time for the ionic current in a nematic cell under a large electric field.

We evaluate the ionic relaxation time of a nematic cell subjected to a potential difference, V0 , very large with respect to VT=KBT/q=0.025 V, where KBT is the thermal energy, and q the electrical charge of the ions, assumed monovalent. The analysis is performed by assuming that the mobilities of the positive and negative ions are the same, and that the ions can be considered pointlike. We show that, for V0>>VT, the relaxation time tends to the time of flight of the ions. In our analysis the ionic charges are assumed to form two surface layers responsible for a partial screening of the external field. In this framework, the evolution of the surface-charge density is determined by a simple differential equation related to the conservation of the ions number. According to our calculations, the relaxation time of the surface density of ionic origin, and of the electrical potential close to the electrodes, depends on the applied voltage, in agreement with the experimental observations.

[Induce or not induce labor in gestational diabetes]. / Les indications obstétricales dans le diabète gestationnel: déclencher ou ne pas déclencher.

The most serious hazard of gestational diabetes is shoulder dystocia, which sometimes is complicated by Erb's palsy and maternal lacerations. This risk is linked to fetal weight, and is more frequent in cases of diabetes. So, a caesarean section performed when macrosomia is present is required and an induction of labor before severe macrosomia is proposed. Unfortunately, estimation of fetal weight is imprecise in spite of formulas from fetal parameters. Abdomen circumference (AC) alone is as effective as complex formulas. So, it is proposed to perform an elective section when AC is equal or above 38 cm, and to induce labor, after 38 weeks of gestation, for limiting the risk of macrosomia when AC is between 35 and 38 cm. Induction is also proposed when pregnancy is complicated by hypertension or when fetal heart septal hypertrophy occurs. The management of gestational diabetes means a strict control of glycemia, which can reduce macrosomia and the need for cesarean section or induction of labor.