Multicenter methodology comparison of the FDA and ISO standard for measurement of in vitro UVA protection of sunscreen products.

In vitro standard methods are available and accepted worldwide to assess UVA protection of sunscreen products. Though, harmonisation of methods has made progress in the last decade, still two differing methods - one by FDA the other by ISO - are in use. In a multicentre study including 9 centres in Germany, 4 different commercial sunscreen products were assessed using both methods to discover their similarities and differences. UVA protection factor and Critical Wavelength were detected at various substrate type (sandblasted versus moulded PMMA plates), at different surface roughness of the plates as well as at different product application dose using two different irradiation spectra. Results: The strongest influence on UVA protection factor results from the surface roughness of the plates. Depending on the roughness (accepted range of 2 to 7 µm in the FDA method) a variability in the UVA protection factor of up to 25% was observed, while the much narrower definition of plate roughness by ISO (4.5 to 5.2 µm) had no relevant influence on the test results. Sandblasted plates in our assessment led to higher UVA protection factors and produced less scattered results compared to moulded plates. These differences were not pronounced. Application dose and spectra of the irradiation source were of negligible influence on UVA protection factor results for the investigated UV-filter combinations. The UVA protection factor which is the endpoint of the ISO method was found to be a parameter with a high potential to differentiate among different test products. The endpoint of the FDA method - the Critical Wavelength - was found to be an unambitious endpoint. Insensitivity to all described modifications of the method was observed. All investigated products performed similar and passed the Critical Wavelength criteria independent of method and parameters.

Gentamicin alters Akt-expression and its activation in the guinea pig cochlea.

Gentamicin treatment induces hair cell death or survival in the inner ear. Besides the well-known toxic effects, the phosphatidylinositol-3 kinase/Akt (PI3K/Akt) pathway was found to be involved in cell protection. After gentamicin application, the spatiotemporal expression patterns of Akt and its activated form (p-Akt) were determined in male guinea pigs. A single dose of 0.1 mL gentamicin (4 mg/ear/animal) was intratympanically injected. The auditory brainstem responses (ABRs) were recorded prior to application and 1, 2 and 7 days afterward. At these three time points the cochleae (n=10 in each case) were removed, transferred to fixative and embedded in paraffin. Seven ears were used as untreated controls. Gentamicin, Akt and p-Akt were identified immunohistochemically in various regions of the cochlea and their staining intensities were quantified on sections using digital image analysis. The application of gentamicin resulted in hearing loss with a concomitant up-regulation of Akt-expression in the organ of Corti and spiral ganglion cells and an additional activation in spiral ganglion cells. At the level of individual ears, clear intracellular correlations were found between Akt- and p-Akt-expression in the stria vascularis and interdental cells and, to a minor extent, in the spiral ligament and the organ of Corti. Furthermore, statistical evidence for the connection between gentamicin up-take and hearing loss was detected. The increase in Akt- and p-Akt-expression in the organ of Corti and spiral ganglion cells indicates a selected response of the cochlea against gentamicin toxicity.

Influence of different cosmetic formulations on the human skin barrier.

The human skin barrier is an important part of the skin's intactness and its functionality is a precondition for healthy skin. Ingredients in cosmetic formulations, especially penetration enhancers, can influence this barrier function as they transport active agents into deeper skin layers. In this study different cosmetic formulations were tested by 60 healthy female volunteers over a period of 4 weeks. The skin hydration and barrier function before and during the application were measured. Significant changes in both parameters were determined. A negative influence on the barrier function by penetration enhancers could be observed, but it was also found that lamellar lipid structures (DermaMembranSysteme®, DMS®) are able to enhance the skin barrier. Both penetration enhancers as well as DMS can increase skin hydration.

17ß-Estradiol reduces nitric oxide production in the Guinea pig cochlea.

Intense noise exposure and the application of ototoxic substances result in increased levels of reactive oxygen species (ROS) and reactive nitrogen species (RNS), such as nitric oxide (NO). In order to reduce the free NO concentration in the inner ear under pathological conditions, the use of natural cytoprotective substances such as 17ß-estradiol is a promising therapeutic concept. In male guinea pigs the organ of Corti and the lateral wall were isolated from the cochlea and afterwards incubated for 6 h in cell-culture medium. 17ß-Estradiol was adjusted in 2 concentrations to organ cultures of the right ears (12 animals per concentration). The left ears were used as controls. The NO production was quantified in the supernatant by chemiluminescence after incubation. Depending on the concentration, 17ß-estradiol reduced NO in the organ of Corti by 43% (p=0.015) and 46% (p=0.026), respectively. In the lateral wall, the NO concentration was reduced by 24%, but without statistical significance (p=0.86). However, when analyzing the association between the 2 cochlear regions for each animal separately, the NO concentrations were lower in nearly all 17ß-estradiol-treated ears compared to controls. In order to demonstrate the flexibility of the organ culture system, the NO donor DETA NONOate and the nitric oxide synthase inhibitors L-NAME and L-NMMA were applied. The electron microscopic analysis revealed a well-preserved cochlear cell morphology after incubation. The ability of 17ß-estradiol to influence the NO production preferentially in the organ of Corti might offer new therapeutic perspectives for inner ear protection.

Internet-based lay person rating of facial photographs to assess effects of a cleansing product and a decent cosmetic foundation on the attractiveness of female faces.

It is well established that decorative cosmetics can enhance female facial attractiveness. In this study, we investigated the effects of a cleanser and a decent foundation on attractiveness of female faces. Comparative rating of a set of facial photographs by a group of lay persons revealed that the cleansing product was significantly reducing the attractiveness of the stimulus persons. Treatment with the foundation increased the attractiveness of the female faces clearly. The authors conclude that even unobtrusive cosmetic treatments like cleansers and light foundations may cause relevant changes of the attractiveness of female faces.

The VEGF/VEGF-R axis in sporadic vestibular schwannomas correlates with irradiation and disease recurrence.

BACKGROUND/AIMS: The molecular mechanisms downstream of mutated neurofibromatosis type 2 (NF2) gene resulting in the growth and development of vestibular schwannoma (VS) are controversial. Several lines of evidence suggest the involvement of the vascular endothelial growth factor (VEGF) pathway in VS development. Given that recent studies of VEGF blockade in patients with NF2-associated VS showed positive effects on VS growth control, we initiated this comprehensive study of the VEGF pathway in sporadic VS. METHODS: A tissue microarray analysis of 182 sporadic VS was conducted. The expression of VEGF and its receptors as well as the proliferative activity of the tumors were quantified. The expression data were correlated to tumor volumes and diameters as well as to tumor recurrence and previous irradiation. RESULTS: All studied tumors expressed VEGF and its receptors. Proliferative activity was related to the growth characteristics of the tumors. Moreover, we found significantly higher VEGF levels in recurrent tumors (p = 0.0387) and in preoperatively irradiated tumors (p = 0.0213). CONCLUSION: Our data suggest a relevant role of the VEGF pathway in VS growth and therapy outcome. Therefore, targeting this pathway using antiangiogenic compounds might be beneficial for patients with sporadic VS, especially those with recurrent or irradiated tumors.

An encapsulated fruit and vegetable juice concentrate increases skin microcirculation in healthy women.

BACKGROUND/AIM: Microcirculation in the dermis of the skin is important for nutrient delivery to this tissue. In this study, the effects of a micronutrient concentrate (Juice Plus+®; 'active group'), composed primarily of fruit and vegetable juice powder, on skin microcirculation and structure were compared to placebo. STUDY DESIGN/METHODS: This 12-week study had a monocentric, double-blind placebo and randomized controlled design with two treatment groups consisting of 26 healthy middle-aged women each. The 'oxygen to see' device was used to evaluate microcirculation. Skin density and thickness were measured using ultrasound. Measurements for skin hydration (Corneometer®), transepidermal water loss and serum analysis for carotenoids and α-tocopherol were also performed. RESULTS: By 12 weeks, microcirculation of the superficial plexus increased by 39%. Furthermore, skin hydration increased by 9% while skin thickness increased by 6% and skin density by 16% in the active group. In the placebo group, microcirculation decreased, and a slight increase in skin density was observed. CONCLUSION: Ingestion of a fruit- and vegetable-based concentrate increases microcirculation of the skin at 12 weeks of intervention and positively affects skin hydration, density and thickness.

[Possible molecular mechanisms of spontaneous remission in sudden idiopathic hearing loss]. / Mögliche molekulare Mechanismen einer Spontanremission nach Hörsturz.

According to current knowledge, it must be assumed that temporary idiopathic hearing loss and its spontaneous remission are based on mechanical and/or pathological alterations in the inner ear. The causal mechanisms might be based on inter-individual variations. Induced by dose-dependent activators, temporary as well as permanent damage might occur. Sudden hearing loss may be initiated by an increase in the local nitric oxide (NO) concentration. Spontaneous remission, i.e. functional restoration, can be explained by a local decrease in the NO concentration. In this context, regulatory systems such as the gap-junction system, blood vessels or synapses might be affected. In addition, alterations in the hormone level of estrogen and mineralocorticoids, as well as cellular glutathione and vitamin levels, might lead to temporary alterations in the inner ear. Recent experimental findings indicate a role for the shuttle protein Survivin in the spontaneous remission of sudden hearing loss.

Genomic changes in salivary gland pleomorphic adenomas detected by comparative genomic hybridization.

The aim of this study was to investigate whether so far unknown chromosomal alterations in pleomorphic adenoma (PA) exist. To this end, tissue samples from 18 patients with parotid gland PA were studied by comparative genomic hybridization (CGH) using Phi-29-DNA-polymerase for DNA amplification. The most common aberrations were losses of chromosomal material of 19p (6/18), 9q, 16p, and 19q (in 3 out of 18 patients each). Additional losses were observed on 4p, 5q, and 17q (2 / 18 each). Gains involved chromosomes 2p, 4p, 6p, 17q, and 21q (2 / 18 each). Losses of 19p have been associated with inactivation of tumor-suppressor genes in carcinomas previously. As a result, pleomorphic adenomas show a considerable diversity of chromosomal gains and losses detected by CGH. The 19p arm, and particularly its 19p13 region, need be further studied to elucidate the potential impact of associated lost tumor suppressor genes on PA development.

Supplementation of flaxseed oil diminishes skin sensitivity and improves skin barrier function and condition.

BACKGROUND: Skin sensitivity is a common problem in the Western population correlated with changes of skin properties like skin barrier function, hydration and skin physiology. Skin properties can be modulated by dietary fatty acids (FA), especially poly-unsaturated FA. The present study was performed to evaluate the effect of daily supplementation with flaxseed oil and safflowerseed oil on healthy volunteers with sensitive skin. METHODS: The study was designed as a randomized, double-blind 12-week intervention with 2 female treatment groups (n = 13). Plasma FA profile, skin sensitivity, skin hydration, transepidermal water loss (TEWL) and skin surface were evaluated on day 0, week 6 and week 12. RESULTS: Supplementation with flaxseed oil led to significant decreases in sensitivity (after nicotinate irritation), TEWL, skin roughness and scaling, while smoothness and hydration were increased. Concomitantly, the ratio of n-6/n-3 FA in plasma decreased. Upon supplementation with safflowerseed oil, only a significant improvement in skin roughness and hydration was observed; however, the effects were less pronounced and determined at a later point in time than with flaxseed oil. The plasma n-6/n-3 FA ratio increased. CONCLUSION: The data provide evidence that daily intake of flaxseed oil modulates skin condition.

In vitro sun protection factor: still a challenge with no final answer.

In the past, several attempts have been made to develop in vitro methods for determining protection against UV radiation. To date however, there is no broadly accepted method. Various known and unknown parameters influence the transmission measurements of scattering films, such as the multifaceted compositions of sunscreens, the technical limitations of measurement devices as well as the difficulty to apply very thin films of sunscreen in a reproducible manner throughout different laboratories. In vitro data were measured in this multicenter study to compare possible methodologies and strategies for an in vitro approach to the sun protection factor (SPF). This publication will not present a final in vitro SPF test method, but it will point out which technical side effects may influence such a method. Influential factors such as the quality of spectrophotometer used, the amount of product applied, pretreatment of samples, time and temperature of equilibration, size of the measured surface, the application process or the calculation on the basis of standardized data are presented and discussed. Finally, a reduction of the standard deviations within single laboratories could be realized for in vitro SPF testing, but no improvement of the interlaboratory comparison was obtained. The development of a valid and reliable SPF in vitro test still remains a challenge, and further work is necessary to develop a satisfactory method.

An otoprotective role for the apoptosis inhibitor protein survivin.

Hearing impairment caused by ototoxic insults, such as noise or gentamicin is a worldwide health problem. As the molecular circuitries involved are not yet resolved, current otoprotective therapies are rather empirical than rational. Here, immunohistochemistry and western blotting showed that the cytoprotective protein survivin is expressed in the human and guinea pig cochlea. In the guinea pig model, moderate noise exposure causing only a temporary hearing impairment transiently evoked survivin expression in the spiral ligament, nerve fibers and the organ of Corti. Mechanistically, survivin upregulation may involve nitric oxide (NO)-induced Akt signaling, as enhanced expression of the endothelial NO synthase and phosphorylated Akt were detectable in some surviving-positive cell types. In contrast, intratympanic gentamicin injection inducing cell damage and permanent hearing loss correlated with attenuated survivin levels in the cochlea. Subsequently, the protective activity of the human and the guinea pig survivin orthologs against the ototoxin gentamicin was demonstrated by ectopic overexpression and RNAi-mediated depletion studies in auditory cells in vitro. These data suggest that survivin represents an innate cytoprotective resistor against stress conditions in the auditory system. The pharmacogenetic modulation of survivin may thus provide the conceptual basis for the rational design of novel therapeutic otoprotective strategies.

Effects of dehydroepiandrosterone therapy on pubic hair growth and psychological well-being in adolescent girls and young women with central adrenal insufficiency: a double-blind, randomized, placebo-controlled phase III trial.

CONTEXT AND OBJECTIVE: The efficacy of oral dehydroepiandrosterone (DHEA) in the treatment of atrichia pubis and psychological distress in young females with central adrenal insufficiency is unknown. Our study aimed to evaluate this therapy. DESIGN AND PATIENTS: A total of 23 young females (mean age 18 yr, range 13-25) was enrolled in a double-blind randomized placebo-controlled trial. Inclusion criteria were ACTH deficiency plus two or more additional pituitary deficiencies, serum DHEA less than 400 ng/ml, and pubertal stage more than B2. Exclusion criteria were cerebral radiation with more than 30 Gy, tumor remission less than 1 yr, amaurosis, hypothalamic obesity, psychiatric disorders, and unstable hormone medication. INTERVENTION: Patients were randomized to placebo (n = 12) or 25 mg HPLC-purified DHEA/d (n = 11) orally for 12 months after stratification into a nontumor (n = 7) and a tumor group (n = 16). MAIN OUTCOME MEASURES: Clinical scoring of pubic hair stage was performed at 0, 6, and 12 months (primary endpoint), and psychometrical evaluation (Symptom Check-List-90-R and the Centre for Epidemiological Studies-Depression Scale) at 0 and 12 months (secondary endpoint). Androgen levels and safety parameters were measured at 0, 6, and 12 months; 24-h androgen urinary excretion rates were calculated at 0 and 12 months. RESULTS: In the placebo group, four patients dropped out because of recurrence of craniopharyngioma, manifestation of type 1 diabetes, and change of residence (n = 2); in the DHEA group, one patient dropped out because of recurrent anxiety attacks. DHEA substitution resulted in normalization of DHEA sulfate and androstanediol glucuronide morning serum levels 2 h after drug intake (P < 0.006), and of its 24 h urinary metabolite levels (P < 0.0001), placebo had no effect. Morning serum levels of androstenedione increased in the DHEA group (P < 0.02) but did not normalize. The DHEA group exhibited significant progress in pubic hair growth from Tanner stage I-III to II-V (mean: +1.5 stages), whereas the placebo group did not (relative risk 0.138; 95% confidence interval 0.021-0.914; P = 0.0046). Importantly, eight of the 10 Symptom Check-List-90-R scores, including those for depression, anxiety, and interpersonal sensitivity, and the global severity index improved in the DHEA group in comparison to the placebo group (P < 0.048). DHEA was well tolerated. CONCLUSIONS: In adolescent girls with central adrenal insufficiency, daily replacement with 25 mg DHEA orally is beneficial: atrichia pubis vanishes, and psychological well-being improves significantly.

[Protection of the cochlea by ascorbic acid in noise trauma]. / Protektion der Kochlea durch Vitamin C bei Lärmexposition.

BACKGROUND: The protective effect of ascorbic acid against noise-induced hearing loss and increased nitric oxide (NO) formation after noise exposure have already been demonstrated in animal models. However, the influence of ascorbic acid on noise-induced NO production within the cochlea is still unclear. METHODS: Guinea pigs (n=48) were fed for 7 days with low [25 mg/kg bodyweight (bw)/day] and high (525 mg/kg bw/day) doses of ascorbic acid. Then half of the animals were exposed to noise (90 dB for 1 h). The hearing levels were recorded beforehand, on the 3rd and 7th days after feeding, and directly after noise exposure. Finally, the organ of Corti and the lateral wall were removed from the inner ear and incubated separately for 6 h in culture medium, and the nitrite content was determined in the supernatant. RESULTS: Compared with low-dose feeding, feeding of high doses of ascorbic acid resulted in a reduction of hearing impairment of about 8 dB after noise exposure. A correlation between hearing improvement and decreased NO production was detectable for both cochlea regions but was more pronounced in the lateral wall. CONCLUSION: A high dose of ascorbic acid lowers NO production in the inner ear, reduces hearing loss, and protects the cochlea from nitroactive stress.

Change in skin physiological parameters in space--report on and results of the first study on man.

Astronauts often show skin reactions in space. Systematic tests, e.g. with noninvasive skin physiological test methods, have not yet been done. In an interdisciplinary cooperation, a test series with skin physiological measurements was carried out before, during and after a long-term mission in the International Space Station. The hydration of the stratum corneum (Corneometer), transepidermal water loss (Tewameter), and the surface structure of the skin (SkinVisiometer) were measured. In order to record cutaneous states, the suction elasticity was measured (Cutometer), and an ultrasound measurement with 20 MHz (DermaScan) was also made. In addition, one measuring field of the two inner forearms was treated with a skin care emulsion. There were indications of a delayed epidermal proliferation of the cells, which would correspond to the clinical symptoms. Hydration and TEWL values are improved by respective skin care. On the cutaneous level, the elasticity measurements and the ultrasound picture showed results which correspond to a significant loss of elasticity of the skin. Further examinations are necessary to validate these preliminary results.

In vivo assessment of Ectoin: a randomized, vehicle-controlled clinical trial.

The aim of the study was to assess an Ectoin formulation with regard to the antiageing properties. The study was designed as a monocentric, randomized, double-blind application test, in order to ensure the compatibility and the efficacy of Ectoin in comparison to a vehicle emulsion. A total of 104 voluntary healthy female test subjects were included in the study. Moisturizing properties as well as other parameters of skin ageing, like skin surface structure and skin elasticity, were determined for treatment A (vehicle) and treatment B (with 2% Ectoin) versus an untreated control. Statistical evaluations according to the Wilcoxon rank-sum test indicate a general preference for the Ectoin treatment by the test subjects in both the application and the efficacy tests. None of the participating test subjects had any side effects throughout the study. In terms of antiageing properties, previous in vitro studies could be confirmed by this clinical trial, clarifying that the natural cell protection concept of Ectoin is transferable to skin care with manifold benefits.

Influence of applied quantity of sunscreen products on the sun protection factor--a multicenter study organized by the DGK Task Force Sun Protection.

It is often debated that the protection against solar-induced erythema under real conditions is dependent upon the amount of sunscreen applied. It is believed that when too little is applied a lower sun protection than indicated on the label will result. The aim of this study was to quantify this effect. In this multicenter study, the influence of three different amounts (0.5, 1.0, 2.0 mg/cm(2)) of three commercial sunscreen products in three reliable test centers was investigated according to the test protocol of The International Sun Protection Factor Test Method. The main result was a linear dependence of the SPF on the quantity applied. Taking into consideration the volunteer-specific variations, an exponential dependence of confidence interval of the in vivo SPF and amount applied was found. The highest amount applied (2.0 mg/cm(2)) was linked to the lowest confidence intervals. Thus, from the point of view of producing reliable and reproducible in vivo results under laboratory conditions, the recommendation of this multicenter study is an application quantity of 2.0 mg/cm(2).

In vitro assessment of water resistance of sun care products: a reproducible and optimized in vitro test method.

The aim of the study was to develop a simple reproducible and reliable in vitro water resistance (WR) method to assess the sun care products. This paper is the result of a scientific collaboration between seven different international industrial laboratories and testing institutes. The same group has already achieved an in vitro protocol for the sun protection factor (SPF) determination [1]. The in vitro WR of sunscreens was tested by applying the same principle as in vivo, which determines the percentage of retention of sunscreen products by assessing the SPF before and after water immersion. Special care was taken to study the parameters influencing the WR and the possibility to follow the kinetics of sunscreen retention during water immersion. The influence of different water qualities has been tested, and osmosed water (1-3 microS cm(-1)) was chosen for the main ring study. Measurement was carried out after 5, 20 and 40 min of immersion. Histograms of selected products demonstrate the percentage of WR at all measuring times and centres, and the regression coefficient to the in vivo determination was shown and statistical calculations clearly demonstrate the reproducibility of the results between the different evaluation centres. The presented method is a practical, convenient and relevant tool for WR screening of sun care and skin care products. It even has the potential to be the starting point for the replacement of the in vivo method in future.

Proof of partial imbalances 6q and 11q due to maternal complex balanced translocation analyzed by microdissection of multicolor labeled chromosomes (FISH-MD) in a patient with Dandy-Walker variant.

We report on a family in which a daughter is described with mental retardation, as well as malformations of the heart, and of the brain (Dandy-Walker variant). The patient's phenotype suggests a chromosomal rearrangement. However, her karyotype was unremarkable by conventional cytogenetic analysis. In order to detect chromosome rearrangements overseen by this method, the subtelomere regions of suspicious chromosomes were verified by fluorescence in situ hybridization (FISH). A rearranged derivative chromosome 6 was identified. Further examinations by FISH-microdissection (FISH-MD) revealed a maternal complex balanced translocation. The patient inherited the derivative chromosome 6 from her mother and therefore carries a partial monosomy 6q26-->qter and a partial trisomy 11q23.3-->qter.

Antioxidant supplements improve parameters related to skin structure in humans.

In the present study we investigated the influence of two different antioxidant supplements composed of carotenoids, vitamin E and selenium on parameters related to skin health and skin aging. Thirty-nine volunteers with healthy, normal skin of skin type 2 were divided into 3 groups (n = 13) and supplemented for a period of 12 weeks. Group 1 received a mixture of lycopene (3 mg/day), lutein (3 mg/day), beta-carotene (4.8 mg/day), alpha-tocopherol (10 mg/day) and selenium (75 microg/day). Group 2 was supplemented with a mixture of lycopene (6 mg/day), beta-carotene (4.8 mg/day), alpha-tocopherol (10 mg/day) and selenium (75 microg/day). Group 3 was the placebo control. Upon supplementation serum levels of selected carotenoids increased in both verum groups. Skin density and thickness were determined by ultrasound measurements. A significant increase for both parameters was determined in the verum groups. Roughness, scaling, smoothness and wrinkling of the skin were determined by Surface Evaluation of Living Skin (Visioscan). Roughness and scaling were improved by the supplementation with antioxidant micronutrients. In the placebo group no changes were found for any of the parameters.