Estrogen and skin. An overview

Comparison of Lip Revision Rates in Traditional Versus Early Cleft Lip Repair: An Institutional Review

BACKGROUND

Traditional cleft lip repair (TLR) is performed between 3 and 6 months of age. For over 10 years, our institution has transitioned from offering presurgical nasoalveolar molding (NAM) before cleft lip repair to performing early cleft lip repair (ECLR) within 2 to 5 weeks of life, circumventing the use of NAM.

PURPOSE

This study aimed to estimate and compare the lip revision rates between patients who underwent ECLR versus TLR ± NAM.

STUDY DESIGN, SETTING, SAMPLE

A retrospective cohort study was conducted. Patients with nonsyndromic unilateral cleft lip who underwent primary repair between 2004 and 2021 at Children's Hospital Los Angeles were included. Exclusion criteria were as follows: American Society of Anesthesiologists classification III or higher, syndromic or bilateral cases, gestational-corrected age of more than 6 months at lip repair, and less than 2 years of follow-up.

PREDICTOR VARIABLE

The predictor variable was the timing of primary cleft lip repair. Subjects were allocated to 1 of 2 treatment cohorts: ECLR (<3 months) and TLR ± NAM (3 to 6 months).

MAIN OUTCOME VARIABLE

The primary outcome was lip revision surgery at any time during the patient's cleft care. Secondary outcomes included the extent and timing of the revision surgeries.

COVARIATES

Data collection included presurgical NAM use, surgeon, cleft phenotype, and cleft width ratio.

ANALYSES

A 2-phased coarsened exact matching process was performed to match cohorts based on surgeon, cleft phenotype, and cleft width ratio at a 1:1 ratio. Kaplan-Meier analyses were used to estimate and compare the revision rates.

RESULTS

A total of 1,101 patients underwent primary repair during the study period. After applying the exclusion criteria, 362 patients remained before matching. Among these, 154 patients (77 ECLR, 77 TLR ± NAM) were included after matching. Kaplan-Meier analysis estimated a lower 5-year revision rate for the ECLR cohort compared to the TLR ± NAM cohort (17.3 vs 32.6%, log-rank P < .05). Median follow-up time was 6.6 years [interquartile range 4.4 to 9.2].

CONCLUSIONS AND RELEVANCE

ECLR resulted in approximately a 2-fold reduction in lip revision rates compared with TLR ± NAM. These findings suggest that cleft lip repair at approximately 1 month of age may decrease the burden of secondary procedures later in life.

Photoaging: Current Concepts on Molecular Mechanisms, Prevention, and Treatment

Photoaging is the consequence of chronic exposure to solar irradiation, encompassing ultraviolet (UV), visible, and infrared wavelengths. Over time, this exposure causes cumulative damage, leading to both aesthetic changes and structural degradation of the skin. These effects manifest as rhytids, dyschromia, textural changes, elastosis, volume loss, telangiectasias, and hyperkeratosis, collectively contributing to a prematurely aged appearance that exceeds the skin's chronological age. The hallmarks of photoaging vary significantly by skin phototype. Skin of color tends to exhibit dyschromia and features associated with "intrinsic" aging, such as volume loss, while white skin is more prone to "extrinsic" aging characteristics, including rhytids and elastosis. Moreover, susceptibility to different wavelengths within the electromagnetic spectrum also differs by skin phototype, influencing the clinical presentation of photoaging, as well as prevention and treatment strategies. Fortunately, photoaging-and its associated adverse effects-is largely preventable and, to some extent, reversible. However, effective prevention and treatment strategies require careful tailoring to an individual's skin type. In this review, we summarize molecular mechanisms underlying photoaging, examine its clinical manifestations, outline risk factors and prevention strategies, and highlight recent advancements in its treatment.

Optimizing Outcomes in Breast Reconstruction: The Role of Hormonal Therapy Management

BACKGROUND

Breast cancer comprises diverse subtypes with prognostic and therapeutic implications. Hormone therapy plays a crucial role in managing tumors expressing hormonal receptors, but its impact on breast reconstruction outcomes remains unclear. This study aims to evaluate the association between perioperative hormone therapy continuation and the incidence of postoperative complications following breast reconstruction (including autologous, prosthetic, and hybrid techniques), with a focus on identifying specific complication types to refine patient management strategies.

METHODS

A retrospective analysis was conducted on patients who underwent breast reconstruction following mastectomy for hormone receptor-positive breast cancer. Patients were categorized based on the appropriate discontinuation of hormonal therapy. Clinical data, including patient characteristics, treatment regimens, and complication occurrences, were registered and analyzed.

RESULTS

Inadequate suspension of hormonal therapy during the perioperative period was significantly associated with a higher rate of complications, particularly in the immediate and early phases. Complications such as skin alterations, flap failure, seroma development, and clinical infection showed significant associations with the continuation of hormone therapy (p < 0.05). No significant differences were observed for other complications.

CONCLUSIONS

Preliminary findings suggest a potential correlation between the continuation of hormone therapy during the perioperative phase and the development of complications following breast reconstruction.

How Hormonal Balance Changes Lives in Women with Psoriasis

Psoriasis is a chronic, immune-mediated skin disease significantly impacting women, with disease severity often modulated by hormonal fluctuations. This review examines the influence of hormonal changes on the course of psoriasis in women, focusing on key life stages-including the menstrual cycle, pregnancy, postpartum, and menopause-and their impact on disease progression and symptomatology. Estrogen, the principal female sex hormone, plays a critical role in immune modulation. Variations in estrogen levels, which occur naturally throughout a woman's life, are associated with fluctuations in psoriasis severity. Low estrogen levels, as seen during menstruation or menopause, are linked to symptom exacerbation, while elevated levels during pregnancy may reduce symptoms in some women. However, responses are variable, with others experiencing no change or worsening during pregnancy. Postpartum, the rapid decline in estrogen often triggers severe flare-ups, while menopause, marked by a sustained estrogen reduction, frequently correlates with increased disease severity and flare frequency. The review also addresses the profound impact of psoriasis on women's quality of life, including physical discomfort, psychological distress, and social stigma. Additionally, fertility concerns are discussed, as severe psoriasis and associated treatments may increase the risk of adverse pregnancy outcomes. Consideration is given to hormonal therapies, lifestyle modifications, and their effects on psoriasis, underscoring the need for personalized treatment approaches that account for hormonal influences. Understanding these hormonal dynamics is essential for developing targeted, effective management strategies that enhance quality of life for women affected by psoriasis.

Treatment of menopausal skin - A narrative review of existing treatments, controversies, and future perspectives

Menopause is a state of estrogen deficiency that affects numerous estrogen-dependent tissues in the female body. Skin is one of the most affected organs. Many consider menopausal skin changes to be merely an aesthetic problem; however, they can significantly affect women's quality of life. Currently, there are no approved effective treatments to prevent or alleviate skin changes associated with estrogen deficiency. Standard systemic hormone replacement therapy used to treat menopausal symptoms may be effective to some degree for skin treatment. In addition, compounded bioidentical hormone replacement therapy, selective estrogen receptor modulators, and phytoestrogens could also be used for skin treatment, although this is only hypothetical due to lack of data. Many questions therefore remain unanswered. On the other hand, topical, low-dose estrogen that would act only on the skin without systemic effects could be a possible option, as could be skin-only acting topical phytoestrogens. Such topical products without systemic effects could play a role in the treatment of menopausal skin. However, they are not currently approved because there is insufficient data on their safety and efficacy. A healthy lifestyle could have a positive effect on the menopausal skin. In this review, we provide an overview of the characteristics of menopausal skin, an outlook on the future treatment of menopausal skin with estrogens and other approaches, and the associated controversies and speculations. Overall, the importance of menopausal skin changes should not be neglected, and high-quality research is needed to gain new insights into the treatment of menopausal skin.

Small molecule conjugates with selective estrogen receptor β agonism promote anti-aging benefits in metabolism and skin recovery

Estrogen is imperative to mammalian reproductivity, metabolism, and aging. However, the hormone activating estrogen receptor (ERs) α can cause major safety concerns due to the enrichment of ERα in female tissues and certain malignancies. In contrast, ERβ is more broadly expressed in metabolic tissues and the skin. Thus, it is desirable to generate selective ERβ agonist conjugates for maximizing the therapeutic effects of ERs while minimizing the risks of ERα activation. Here, we report the design and production of small molecule conjugates containing selective non-steroid ERβ agonists Gtx878 or genistein. Treatment of aged mice with our synthesized conjugates improved aging-associated declines in insulin sensitivity, visceral adipose integrity, skeletal muscle function, and skin health, with validation in vitro. We further uncovered the benefits of ERβ conjugates in the skin using two inducible skin injury mouse models, showing increased skin basal cell proliferation, epidermal thickness, and wound healing. Therefore, our ERβ-selective agonist conjugates offer novel therapeutic potential to improve aging-associated conditions and aid in rejuvenating skin health.

Ingenuity pathway analysis of gingival epithelial cells stimulated with estradiol and progesterone

OBJECTIVE

Periodontal disease is a risk factor for preterm delivery, and elevated female hormone levels during pregnancy promote hormone-dependent periodontopathogenic bacterial growth and gingivitis. Although the saliva of pregnant women contains female hormones at elevated levels, their effects on the gingiva are poorly understood. Therefore, in this study, we investigated the effects of estradiol and progesterone stimulation on gingival epithelial cells via ingenuity pathway analysis.

METHODS

Human gingival epithelial progenitors were cultured in a CnT-Prime medium; 17β-estradiol (E2) and progesterone (P4) were used as the reagents. Cells treated with dimethyl sulfoxide alone were used as the control group. Cells in the control and experimental groups were incubated for 12 h. RNA was extracted from the cultured cells, RNA-Seq was performed, and pathway analysis was conducted.

RESULTS

Differentially expressed genes were detected for 699 (over 2-fold increase) and 348 (decrease) genes in group E2 and for 1448 (increase) and 924 (decrease) genes in group P4 compared with those in the control group (FDR <0.05, n = 4). The z-scores of the pathways suggest that E2 and P4 increased the activity of the wound healing signaling pathway. The activation of this pathway was higher in the E2 and P4 groups than that in the control group.

CONCLUSIONS

The results of this study suggest that estradiol and progesterone may affect gingival homeostasis and wound healing.

An extensive review on phenolic compounds and their potential estrogenic properties on skin physiology

Polyphenolic compounds constitute a diverse group of natural components commonly occurring in various plant species, known for their potential to exert both beneficial and detrimental effects. Additionally, these polyphenols have also been implicated as endocrine-disrupting (ED) chemicals, raising concerns about their widespread use in the cosmetics industry. In this comprehensive review, we focus on the body of literature pertaining to the estrogenic properties of ED chemicals, with a particular emphasis on the interaction of isoflavones with estrogen receptors. Within this review, we aim to elucidate the multifaceted roles and effects of polyphenols on the skin, exploring their potential benefits as well as their capacity to act as ED agents. By delving into this intricate subject matter, we intend to provoke thoughtful consideration, effectively opening a Pandora's box of questions for the reader to ponder. Ultimately, we invite the reader to contemplate whether polyphenols should be regarded as friends or foes in the realm of skincare and endocrine disruption.

Does Early Referral Lead to Early Repair? Quality Improvement in Cleft Care

BACKGROUND

Cleft lip and palate is the most common congenital defect of the head and neck, occurring in 1 of 700 live births. Diagnosis often occurs in utero by conventional or 3-dimensional ultrasound. Early cleft lip repair (ECLR) (<3 months of life) for unilateral cleft lip (UCL), regardless of cleft width, has been the mainstay of lip reconstruction at Children's Hospital Los Angeles since 2015. Historically, traditional lip repair (TLR) was performed at 3 to 6 months of life ± preoperative nasoalveolar molding (NAM). Previous publications highlight the benefits of ECLR, such as enhanced aesthetic outcomes, decreased revision rate, better weight gain, increased alveolar cleft approximation, cost savings of NAM, and improved parent satisfaction. Occasionally, parents are referred for prenatal consultations to discuss ECLR. This study evaluates timing of cleft diagnosis, preoperative surgical consultation, and referral patterns to validate whether prenatal diagnosis and prenatal consultation lead to ECLR.

METHODS

Retrospective review evaluated patients who underwent ECLR versus TLR ± NAM from 2009 to 2020. Timing of repair, cleft diagnosis, and surgical consultation, as well as referral patterns, were abstracted. Inclusion criteria dictated: age < 3 months for ECLR or 3 to 6 months for TLR, no major comorbidities, and diagnosis of UCL without palatal involvement. Patients with bilateral cleft lip or craniofacial syndromes were excluded.

RESULTS

Of 107 patients, 51 (47.7%) underwent ECLR whereas 56 underwent TLR (52.3%). Average age at surgery was 31.8 days of life for the ECLR cohort and 112 days of life for the TLR cohort. Furthermore, 70.1% of patients were diagnosed prenatally, yet only 5.6% of families had prenatal consults for lip repair, 100% of which underwent ECLR. Most patients were referred by pediatricians (72.9%). Significance was identified between incidence of prenatal consults and ECLR (P = 0.008). In addition, prenatal diagnosis was significantly correlated with incidence of ECLR (P = 0.027).

CONCLUSIONS

Our data demonstrate significance between prenatal diagnosis of UCL and prenatal surgical consultation with incidence of ECLR. Accordingly, we advocate for education to referring providers about ECLR and the potential for prenatal surgical consultation in the hopes that families may enjoy the myriad benefits of ECLR.

The role of diet in managing menopausal symptoms: A narrative review

Menopause is a natural stage that occurs when women stop menstruating, during which many women experience physical and psychological symptoms that can affect their quality of life and ability to work. Dietary modifications and food supplements may be explored by some women as alternatives to hormone replacement therapy, although existing reviews and expert position statements have given this limited consideration. This narrative review summarises the current evidence for dietary patterns, and botanical and food supplements, in the management of common menopausal symptoms, including vasomotor symptoms (VMS; hot flushes; night sweats), changes in bodyweight and composition, psychological symptoms (depression; anxiety; cognitive changes), sleep disturbances, joint pain, skin changes and urogenital symptoms. Soy isoflavones may reduce the frequency and/or severity of VMS, although results are inconsistent, and it is unclear whether dietary and supplemental sources have comparable effects. Adopting a healthier dietary pattern may support a healthy bodyweight and benefit VMS. However, evidence suggesting dietary patterns may benefit depression, anxiety, and cognition remains largely observational. While some botanicals, such as black cohosh and St John's Wort, have been reported in some studies to alleviate symptoms (such as VMS and depression), these are not currently recommended due to uncertainty about the appropriate dose and preparation, and potential safety concerns. Evidence for other symptoms is currently too limited to draw conclusions. While further trials at different menopausal stages are needed, adopting a healthier dietary pattern in accordance with dietary guidelines is likely to help support women's health before, during and after the menopausal transition.

User Experience in Cosmetics: Perception Analysis Regarding the Use of an Anti-Aging Moisturizer

One of the most important characteristics of aging skin is dehydration, which is why the use of moisturizing products is very important, especially with increasing age. Thus, the user’s experience when using a product is interesting for the companies to develop specific cosmetics not only considering the physiological needs of each skin, but also according to the preference of a group if there is any. For this, a moisturizer was developed, containing an antioxidant active, ascorbyl tetraisopalmitate, whose sensory characteristics were evaluated by 33 Brazilian women between 30 and 60 years old. The results showed that the formulation was well accepted by all subjects, regardless of their age group, initial hydration, or the presence of visible signs of skin aging. It is suggested that the presence of the active ingredient in different concentrations caused a different perception of the formula for specific attributes such as the aqueous residue, film formation, and the feelings of oiliness and stickiness to the skin after application. These results suggest that the perception of the sensory characteristics of the product was more related to the nature and proportion of the compounds than to the age of the subjects.

Rapid Detection of Estrogens in Cosmetics by Chemical Derivatization and Paper-Spray Ionization Mass-Spectrometry

Estrogens in personal care products are harmful to customers. Conventional methods such as HPLC and LC-MS require tedious sample pretreatment and long analytical time. Paper-spray ionization mass spectrometry (PSI-MS) is a powerful tool for the determination of compounds with little time and minimal pretreatment procedures. Since most estrogens show poor responses in PSI-MS, we developed a chemical derivatization and PSI-MS method to determinate three estrogens: estradiol, estriol and ethinyloestradiol with estradiol valerate as the internal standard (I.S.). After derivatization with 2-fluoro-1-methyl-pyridinium-p-toluene-sulfonate, the three estrogens could be quantified in seconds. This method showed good linearity in the range of 0.1~30 μg·mL^-1, with R² > 0.999. Their recovery results were all between 85%~115%. The limits of detection (LOD) were 0.04 μg·mL^-1, 0.02 μg·mL^-1 and 0.02 μg·mL^-1 for estradiol, estriol and ethinyloestradiol respectively, which improved around 200, 2000, and 900 times compared to non-derivative PSI-MS. The method could quantitatively determine estrogens in cosmetics.

Risk factors for the development of idiopathic macular hole: a nationwide population-based cohort study

This nationwide population-based cohort study searched for demographic, comorbid, behavioral, and reproductive risk factors for idiopathic macular hole (MH) development using data provided by the Korean National Health Insurance Service. A total of 4,496,867 individuals aged 50-79 years who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Participants were followed up until December 2018, and incident cases of idiopathic MH were identified. Prospective associations between incident idiopathic MH and various covariates were investigated using multivariable-adjusted Cox proportional hazard models. During an average follow-up period of 4.91 years, 3054 patients were newly diagnosed with idiopathic MHs. Women showed greater risk (hazard ratio of 1.71) and earlier presentation of idiopathic MH than men. Compared to the normal body mass index group, the obese group (≥ 25 kg/m²) showed a significantly lower risk of idiopathic MH. Among postmenopausal women, those with two or more children showed a greater risk of idiopathic MH than those who had not been pregnant, with a hazard ratio of 1.80. In conclusion, idiopathic MH occurred earlier and greater in women. Childbirth were associated with an increased risk of MH development, and obesity was associated with a lower risk of MH.

Tamoxifen Prevents Peritendinous Adhesions: A Preliminary Report

Background

Scarless healing comprises the ultimate goal after an injury. Since tendon healing results in a fibrotic scar, an injured tendon can never regain the mechanical potential and strength of its uninjured form. A wide variety of studies focus on the tendon healing with an absent or minimal peritendinous adhesions. However, no simple method has managed it at all. Possible complex actions and peritendinous environmental events take place during the tendon healing process. Tamoxifen (TAM), besides its breast cancer-related usage, is a potent antifibrotic drug. Here, we aimed to reduce the peritendinous adhesion with TAM administration.

Methods

Achilles tendons of 44 Wistar albino rats were randomly distributed in 4 groups. In group 1, bilateral lower extremities were used as control and sham. Groups 2 and 3 were comprised of low-dose (1 mg/kg) and high-dose (40 mg/kg) systemic administration of TAM, respectively. Group 4 included local administration (1 mg/kg) of TAM. Biomechanical, macroscopical, and histopathological analyses were done and compared statistically. Biomechanically, the maximum force that led to tendon rupture was determined, and tensile force data were recorded via tensile testing device. Macroscopical and histopathological analysis were composed of the quantity, quality, and grade of peritendinous adhesions.

Results

Macroscopic and histopathologic findings revealed that groups 2 and 3 had a variety of values ranging between slight to severe adhesions. In group 2, almost half of the animals had moderate adhesions, whereas in group 3, the majority of the animals had moderate adhesions. There were no animals with moderate or severe adhesions in group 4. Statistically significant values were calculated between sham and control groups. Biomechanically, group 2 showed the most significant result. The tendons in group 2 had the highest stiffness when maximal force was applied to rupture the tendons. Henceforth, all these consequences were proven statistically.

Conclusion

We achieved less peritendinous adhesion with the local administration of TAM when compared to systemic administration of TAM. A better understanding of the peritendinous environmental process will reveal to develop new therapies in the prevention of peritendinous adhesions.

The impact of gender and sex in psoriasis: What to be aware of when treating women with psoriasis

Psoriasis is a common chronic inflammatory skin disease with an exceptionally high burden for women.

The protective effect of co-administration of platelet-rich plasma (PRP) and pentoxifylline (PTX) on cyclophosphamide-induced premature ovarian failure in mature and immature rats

Cyclophosphamide (CP), as an antineoplastic agent, causes premature ovarian failure (POF) due to ovarian toxicity and subsequent infertility in women. Platelet-rich plasma (PRP) has accumulated significant attention in regenerative medicine. Pentoxifylline (PTX) as a methylxanthine derivative has been shown to have antioxidant and antiapoptotic properties. The aim of this study was to evaluate the protective effect of PRP and PTX on CP-induced POF. Fifty mature and immature female rats were assigned into five groups: control, CP (75 mg/kg, intraperitoneal [ip] on days 1 and 10 to induce POF), CP + PRP (200 μl, ip, half an hour after CP injection on day 1 and 10), CP + PTX (50 mg/kg, orally, half an hour after CP injection daily for 21 day), and CP + PRP + PTX. At the end of experiments on day 21, measurement of body weight, ovarian parameters (ovarian volume, follicular granulosa cell layers diameter, oocyte diameter, and the number of granulosa cells), measurement of ovarian hormone in sera for estradiol (E₂), and anti-Mullerian hormone (AMH), as well as biochemical assessment were performed.The results showed that CP significantly reduced the ovarian parameters, E₂, AMH, superoxide dismutase (SOD) activity and increased Malondialdehyde (MDA) levels compared to the control group (p < 0.001). Our results also indicated that all histomorphometric parameters and biochemical markers in CP-induced POF, were preserved close to normal by PRP and PTX treatments in both mature and immature rats (p < 0.001). Therefore, it is concluded that the co-administration of PRP and PTX can protect the ovary from CP-induced POF.

Evaluation of the Number of Follow-up Surgical Procedures and Time Required for Delayed Breast Reconstruction by Clinical Risk Factors, Type of Oncological Therapy, and Reconstruction Approach

BACKGROUND

Breast reconstructive surgery is often a multistage process. The aim was to understand which factors might increase the number of follow-up surgeries and the length of time required to complete the reconstruction process.

METHODS

A cross-sectional analysis was performed. Clinical data of 110 patients who underwent delayed postmastectomy breast reconstruction with a 5-year examination period were reviewed retrospectively. Impact of clinical risk factors, oncological therapy, and reconstruction approach on the number of surgeries and the length of required time was analyzed. Mann-Whitney U test and Kruskal-Wallis rank sum test were used.

RESULTS

In patients undergoing perioperative hormone therapy, an average of 2.9 surgeries and length of 20.2 months were required compared to 2.3 surgeries and 14.0 months in patients without hormone therapy (P = 0.003; P = 0.005). Previous abdominal surgery was associated with an increased number of breast reconstruction stages of 3.1 per patient (P = 0.056) and a longer reconstruction time of 23.0 months (P = 0.050). Patients undergoing nipple reconstruction or implant revision required an increased number of surgeries (P < 0.001; P = 0.012) and a longer reconstruction time (P = 0.002; P < 0.001). Contralateral breast surgery and flap revision were associated only with an increased number of surgeries (P < 0.001; P < 0.001).

CONCLUSION

Perioperative hormone therapy was associated with a significantly higher number of surgeries and duration of time required to complete the reconstruction process. The highest increase in the number of surgeries was in patients with flap revision including anastomosis revision and necrectomy.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Understanding the Sensitive Skin Subject to Achieve a More Holistic Diagnosis

Sensitive skin Syndrome (SSS) is a complex global clinical phenomenon that is defined by the self-reported presence of different sensory perceptions, including tightness, stinging, burning, tingling, pain and pruritus and often without objective signs. Due to the subjective nature of this clinical condition, the diagnosis is complex and there is often a disconnect between what subjects feel and what medical professionals can observe. This chapter reviews the known underlying physiology, some of the triggering factors associated with SSS, co-morbidities as well as the psychological impact on individuals suffering from this condition. The goal is to bridge the gap between the physicians’ understanding and the subjects’ perceptions of this real-life condition that affects so many.

Sagging eye syndrome

The pulley is the functional origin of the extraocular muscles and prevents their dislocation from the muscle cone. The pulley degenerates with age and may progress to cause the sagging eye syndrome (SES). Divergence paralysis, a type of distance esotropia, occurs when the lateral rectus muscle pulley and lateral rectus-superior rectus (LR-SR) band show degenerated symmetry OU. Cyclovertical strabismus of a small angle occurs when the lateral rectus muscle pulley and LR-SR band show degenerated asymmetry OU. Patients with SES have distinctive features, such as baggy eyelids, deep superior sulcus deformity, and aponeurotic ptosis. SES is the leading cause of non-paralytic diplopia, and its rate increases with age, with 60% of the patients being women. One-third of the cases of SES are distance esotropia of 9Δ on average, and two-third of the cases are small-angle hypertropia of 4Δ on average. Diplopia is cured with surgery, and each case needs to be differentiated from the heavy eye syndrome for diagnosis and treatment.

Characterization of skin aging through high-frequency ultrasound imaging as a technique for evaluating the effectiveness of anti-aging products and procedures: A review

INTRODUCTION

High-frequency ultrasound skin imaging analysis (HFUS) is a non-invasive technique that allows a unique approach to the analysis of skin aging, as well as in evaluating the effectiveness of dermatological and cosmetic products, especially for skin rejuvenation.

OBJECTIVE

To describe the impact of skin aging and different anti-aging strategies from the perspective of high-frequency ultrasound.

METHODS

A bibliographic survey was carried out, selecting relevant articles that evaluated the characterization of the skin features from different points of view such as gender (male and female), age (young skin and mature skin), and ethnicity, in addition to individual variations between body regions and daily variations.

RESULTS

Some studies also evaluated the impact of cosmetic treatments and esthetic procedures in the skin. Parameters such as dermal thickness, echogenicity, skin texture, and subepidermal low-echogenic band (SLEB) were analyzed. It can be concluded that there is a trend, although not unanimous in the consequences of aging on the skin, being different between men and women, plus the individual nuances resulted from each one's lifestyle and exposure to the sun.

CONCLUSION

As for the technique, it is concluded that high-frequency ultrasound is an important evaluative alternative for dermatological studies and the effectiveness of anti-aging products and treatments.

Estrogen deficiency - a central paradigm in age-related impaired healing?

Wound healing is a dynamic biological process achieved through four sequential, overlapping phases; hemostasis, inflammation, tissue proliferation and remodeling. For effective wound healing, all four phases must occur in the appropriate order and time frame. It is well accepted that the wound healing process becomes disrupted in the elderly, increasing the propensity of non-healing wound states that can lead to substantial patient morbidity and an enormous financial burden on healthcare systems. Estrogen deprivation in the elderly has been identified as the key driver of age-related delayed wound healing in both genders, with topical and systemic estrogen replacement reversing the detrimental effects of aging on wound repair. Evidence suggests estrogen deprivation may contribute to the development of chronic wound healing states in the elderly but research in this area is somewhat limited, warranting further investigations. Moreover, although the beneficial effects of estrogen on cutaneous healing have been widely explored, the development of estrogen-based treatments to enhance wound repair in the elderly have yet to be widely exploited. This review explores the critical role of estrogen in reversing age-related impaired healing and evaluates the prospect of developing more focused novel therapeutic strategies that enhance wound repair in the elderly via activation of specific estrogen signaling pathways in regenerating tissues, whilst leaving non-target tissues largely unaffected.

Identification of suitable mRNAs and microRNAs as reference genes for expression analyses in skin cells under sex hormone exposure

Quantitative RT-PCR is the most accurate technique for the study of gene expression profiles, however, to ensure the accuracy of qPCR results, suitable reference genes are necessary for data normalization. Hormones influence the development and function of skin cells, regulating the expression of genes and miRNAs. Nevertheless, the stability of reference genes after sex hormone treatment has not been thoroughly investigated. In this study, we evaluated the expression of a set of candidate mRNAs and microRNsA (miRNA) as reference genes in keratinocytes (HaCaT cells), primary human fibroblasts and a melanoma cell line (LM-36 cells) under testosterone or 17β-estradiol treatment. Two algorithms, namely geNorm, Best-Keeper, and the comparative ΔCt method were used to evaluate the expression stability of the candidate reference genes. The comprehensive ranking showed that TBP and miR-191-5p are the most stable expressed genes across all cultured cells under hormone treatment. Furthermore, we observed that GAPDH, HPRT1 and U6 snRNA expression may be altered by hormone exposure, thus, these genes are not recommended as reference genes. In conclusion, the present study provides, to the best of our knowledge, the first evaluation of expressed mRNA(s) and miRNA(s) as reference genes in three different types of skin cells under the stimulation of sex hormones.

S3 Guidelines: Epicutaneous patch testing with contact allergens and drugs - Short version, Part 2

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens.

Prevalence of Sagging Eye Syndrome in Adults with Binocular Diplopia

PURPOSE

Sagging eye syndrome (SES), horizontal and/or vertical strabismus caused by orbital connective tissue degeneration, was first defined 10 years ago. This study investigated SES and other causes of acquired binocular diplopia in adults presenting to a single institution since the description of SES.

DESIGN

Retrospective observational case series.

METHODS

Medical records were reviewed of all new patients over the age of 40 who presented to the Stein Eye Institute with binocular diplopia between January 2015 and December 2018. Clinical causes of diplopia were tabulated in patients grouped by age and sex. In patients with SES, we tabulated binocular alignment, types of treatment, and surgical outcomes.

RESULTS

There were 945 patients of mean age 66.5 years, of whom 514 (54.4%) were female. The most common cause of diplopia was SES (31.4%). The 297 patients with SES were older at 71.2 years (P < 0.0001) and more predominantly female at 59.9% than other patients (52.0%; P = 0.023). The relative proportion of SES patients among all diplopic patients increased with age from 4.7% under age 50 years to 60.9% over the age of 90. Age-related distance esotropia was present in 35% and cyclovertical strabismus in 65% of cases of SES. Strabismus surgery was performed in 50% of cases of SES. Mean esotropia at distance decreased from 6.9 ± 0.7Δ preoperatively to 0.3 ± 0.3Δ postoperatively. Preoperative hypertropia decreased from 3.0 ± 0.3Δ to 0.7 ± 0.2Δ postoperatively. Surgery resolved diplopia in all cases.

CONCLUSIONS

It is important to recognize that SES is a very common cause of adult binocular diplopia.

Catamenial dermatoses associated with autoimmune, inflammatory, and systemic diseases: A systematic review,

Background

Sex hormones are important in female sexual physiology, growth, and homeostasis. Through skin receptors, sex hormones contribute to the dermatologic pathology known as catamenial dermatoses.

Objective

This study aims to summarize the literature on catamenial dermatoses and menses-induced exacerbations of chronic dermatoses.

Methods

This systematic review used the PRISMA method. PubMed was searched using the terms “menses” and “skin” in July 2018, and an assessment was conducted of the relevant literature on skin diseases related to non-pathologic menstruation, such as polycystic ovarian syndrome. Pathology associated with androgenetic acne was excluded from the study.

Results

A total of 102 studies with 1269 female patients were included. The most commonly reported primary catamenial dermatoses were autoimmune progesterone dermatitis and autoimmune estrogen dermatitis. The most commonly reported chronic skin disorders exacerbated by menses were psoriasis, Behcet’s disease, and eczematous dermatoses.

Conclusion

Physicians should be aware of the nature of catamenial dermatoses and their presentation with normal sexual physiology. Patients with chronic dermatoses should be appropriately counseled on menstruation-related exacerbations. Further research needs to be conducted to determine the interplay between immune regulation and sex hormones in catamenial dermatoses and to elucidate effective therapies.

Evolutionary Plasticity in Detoxification Gene Modules: The Preservation and Loss of the Pregnane X Receptor in Chondrichthyes Lineages

To appraise how evolutionary processes, such as gene duplication and loss, influence an organism's xenobiotic sensitivity is a critical question in toxicology. Of particular importance are gene families involved in the mediation of detoxification responses, such as members of the nuclear receptor subfamily 1 group I (NR1I), the pregnane X receptor (PXR), and the constitutive androstane receptor (CAR). While documented in multiple vertebrate genomes, PXR and CAR display an intriguing gene distribution. PXR is absent in birds and reptiles, while CAR shows a tetrapod-specific occurrence. More elusive is the presence of PXR and CAR gene orthologs in early branching and ecologically-important Chondrichthyes (chimaeras, sharks and rays). Therefore, we investigated various genome projects and use them to provide the first identification and functional characterization of a Chondrichthyan PXR from the chimaera elephant shark (Callorhinchus milii, Holocephali). Additionally, we substantiate the targeted PXR gene loss in Elasmobranchii (sharks and rays). Compared to other vertebrate groups, the chimaera PXR ortholog displays a diverse expression pattern (skin and gills) and a unique activation profile by classical xenobiotic ligands. Our findings provide insights into the molecular landscape of detoxification mechanisms and suggest lineage-specific adaptations in response to xenobiotics in gnathostome evolution.

Estrogen-deficient skin: The role of topical therapy

Menopause is a major turning point in a woman's life that is characterized by declining ovarian function and decreased serum estrogen levels. The resulting hormonal changes particularly affect the skin, with postmenopausal symptoms such as loss of structural architecture and increased propensity to damage becoming rapidly noticeable. Interestingly, studies have shown that estrogen deprivation in postmenopausal conditions accelerates many skin changes, including dryness, atrophy, fine wrinkling, and poor wound healing. Thus, the effects of low estrogen on the skin are an important endogenous cause of aging skin in women, yet topical treatment strategies that target cutaneous symptoms are limited. The goal of this article is to provide an overview of the role of estrogen in the skin and changes associated with estrogen deficiency, as well as review alternatives to systemic estrogen therapy and describe the effects of these interventions on cutaneous aging in postmenopausal skin. Specifically, clinical studies that utilize topical estrogens and topical isoflavones, which are soy-derived compounds that interact with estrogen receptors, are discussed.

Local oestrogen therapy modulates extracellular matrix and immune response in the vaginal tissue of post-menopausal women with severe pelvic organ prolapse

This study investigates the effect of local oestrogen therapy (LET) on the expression of proteins participating in collagen/elastin biogenesis and immune markers in vaginal tissues of post‐menopausal women with severe pelvic organ prolapse (POP). Vaginal biopsies were collected from the anterior vaginal wall of informed and consented 52 post‐menopausal women with severe POP undergoing total hysterectomy. Twenty‐nine of the 52 women were treated with LET (in the form of vaginal oestrogen cream or tablet), while the remaining 23 untreated patients served as the controls. This study was approved by Sinai Health System REB. Vaginal tissue specimens were analysed for gene and protein expression using real‐time RT‐PCR and Luminex assays, protein localization and immune cell infiltration were assessed by immunohistochemistry. Forty‐four cytokines were detected. We found that LET application: (a) significantly increased (P < 0.05) gene and protein expression levels of extracellular matrix (ECM) structural proteins, collagen and elastin, as well as the expression of ECM maturation enzyme BMP1; (b) decreased protein expression level of ECM degradation enzymes MMP1, MMP2 and MMP3 accompanied by an increase in their tissue inhibitors, TIMP1 and TIMP4; (c) significantly increased (P < 0.05) the gene and protein expression levels of 14 vaginal cytokines involved in leucocyte infiltration, which was confirmed by immunohistochemistry. Our results indicate that LET plays an important role in the activation of immune system within the local vaginal environment, limiting the undesirable ECM degradation, which supports the strengthening of vaginal ECM in post‐menopausal women, therefore resisting menopause/age‐related changes and inducing urogenital tract tissue regeneration.

Age-related change and sex difference over 60s in disc-fovea angle in Japanese population: the Nagahama Study

PURPOSE

To analyse the disc-fovea angle (DFA) by age group and to compare sex differences in each age group in a large cohort population.

METHODS

This community-based cross-sectional cohort study included 9682 eyes of 9682 volunteers (aged 30-75 years). We measured the DFA, which is the angle between a horizontal line and a line connecting the fovea with the centroid of an optic disc on fundus photographs of the right eye. We manually marked the fovea and surrounded the optic disc. The centroid of an optic disc and the DFA was automatically calculated using originally developed software. We compared the DFA between age groups in 10-year increments and investigated sex differences of DFA in each age group.

RESULTS

Overall mean DFA was 6.32 ± 3.53°. The DFA of older subjects was significantly larger than that of younger subjects (p < 0.001). The DFA of women was larger than that of men in their 60s and 70s (p < 0.001 for both), but not in subjects in their 30s, 40s and 50s.

CONCLUSION

Larger DFA in women than in men in their 60s and 70s suggests the possibility that age-related excyclo-shift occurs more easily in postmenopausal women compared to men of the same age.

Is atopic dermatitis associated with obesity? A systematic review of observational studies

Obesity has been associated with atopic dermatitis (AD); however, the results have been conflicting. Our aim was to provide an update on current knowledge from observational studies addressing the possible association between obesity and AD. Systematic literature review was performed by identifying studies addressing a possible link between AD and overweight/obesity from PubMed, EMBASE and the Cochrane Library in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. A total of 45 studies (comprising more than 90 000 individuals with AD) fulfilled the criteria and were included in the present review. The available studies revealed inconsistencies, but the majority indicated that obesity is associated with AD. Studies addressing obesity in infancy or early childhood (age < 2 years) and AD reported a positive association. From childhood into adulthood, there is a discrepancy in the observations, as the more recent prospective studies found a positive association, whereas this was not observed in older cross-sectional studies. The inconsistency might be explained by the difference in study design, the diagnostic criteria of AD, regional differences, and by the varied definitions of overweight and obesity used in the studies. In Conclusion, overweight/obesity is associated with an increased risk of AD. Large prospective cohort studies are required to confirm the association between AD and obesity and the possibility that weight control in childhood may help to mitigate or reverse AD symptoms.

A preliminary study of uterine scar tissue following cesarean section

AIM

To compare smooth muscle cells, type I collagen, and apoptosis of the lower uterine segment of women who had/without a prior cesarean delivery.

METHODS

Alpha smooth muscle actin (α-SMA), type I collagen, and nuclear apoptosis were compared between the groups from lower uterine segment. Twenty-eight controls and 82 with one prior cesarean delivery were included. The women with a prior cesarean section were classified by time since the surgery: ≤3 years, >3 and ≤5 years, >5 and ≤7 years, >7 and ≤9 years, and >9 years.

RESULTS

Smooth muscle volume density (VD) % was significantly lower in women who had cesarean sections in first three groups than in the controls (all, P<0.01). Type I collagen VD% was similar among all groups and the controls. The number of apoptotic nuclei in the lower uterine segment of the scarred group was greater up to 3 years after surgery and less than in the control at 7-9 years. The number of non-apoptotic nuclei in the scarred group was greater than controls up to 7 years after surgery.

CONCLUSION

The lower uterine segment scar becomes stable at 3 years after cesarean delivery, and by 9 years, the scar is mature.

Human colour in mate choice and competition

The colour of our skin and clothing affects how others perceive us and how we behave. Human skin colour varies conspicuously with genetic ancestry, but even subtle changes in skin colour due to diet, blood oxygenation and hormone levels influence social perceptions. In this review, we describe the theoretical and empirical frameworks in which human colour is researched. We explore how subtle skin colour differences relate to judgements of health and attractiveness. Also, because humans are one of the few organisms able to manipulate their apparent colour, we review how cosmetics and clothing are implicated in courtship and competition, both inside the laboratory and in the real world. Research on human colour is in its infancy compared with human psychophysics and colour research in non-human animals, and hence we present best-practice guidelines for methods and reporting, which we hope will improve the validity and reproducibility of studies on human coloration.This article is part of the themed issue 'Animal coloration: production, perception, function and application'.

The history and basic science development of soy isoflavones

This review summarizes the 2016 NAMS/Pfizer-Wulf H. Utian Endowed Lecture that focused on the history and basic science of soy isoflavones. Described is a personal perspective of the background and history that led to the current interest in soy and isoflavones with a specific focus on the role that soy isoflavones play in the health of postmenopausal women. This overview covers the metabolism and physiological behavior of isoflavones, their biological properties that are of potential relevance to aging, issues related to the safety of soy isoflavones, and the role of the important intestinally derived metabolite S-(-)equol.

Morphological Characteristics of Residual Skin Surface Components Collected from the Surface of Facial Skin in Women of Different Age

Background

Problems of skin aging and its prevention currently attract increasing attention with the growth of human life expectancy. The morphology of the stratum corneum (SC) is well known, but investigation of age-related changes of its structure is difficult in the absence of non-invasive sampling methods. The residual skin surface components (RSSC) that overlay the SC can be easily collected non-invasively.

Objective

The aim of this study was to examine morphology of RSSC samples collected from the surface of facial skin of healthy female volunteers of different age.

Methods

RSSC samples were non-invasively collected from 53 adult female volunteers (22 aged in the range 18∼25 years and 31 aged in the range 50∼73 years). The samples were analysed microscopically.

Results

Distinct age-related changes were determined for lipid droplet size, corneocyte desquamation level and lipid crystal count. There was a significant (p=0.0006) decrease in lipid droplet size among older women. Similarly, significantly (p=0.0401) lower lipid crystal numbers were present in the older group. Conversely, corneocyte desquamation was significantly higher (p=0.0007) in older women. No age-related difference in microbial presence in the RSSC could be detected. Result patterns were generally similar to those previously found in male volunteers; however gender-related differences in the absolute values were revealed.

Conclusion

Non-invasively collected RSSC samples allow identifying age-related changes on facial skin surface. The results of this study highlight gender-dependence of distinct elements of age-associated impairment of epidermal barrier and can be employed for developing new approaches to prevent changes associated with skin aging.

A review of the evidence for threshold of burn injury

INTRODUCTION

Burn injury is common and depth is one measure of severity. Although the depth of burn injury is determined by many factors, the relationship between the temperature of the injurious agent and exposure duration, known as the time-temperature relationship, is widely accepted as one of the cornerstones of burn research. Moritz and Henriques first proposed this relationship in 1947 and their seminal work has been cited extensively. However, over the years, readers have misinterpreted their findings and incorporated misleading information about the time-temperature relationship into a wide range of industrial standards, burn prevention literature and medicolegal opinion.

AIM

The purpose of this paper is to present a critical review of the evidence that relates temperature and time to cell death and the depth of burn injury. These concepts are used by researchers, burn prevention strategists, burn care teams and child protection professionals involved in ascertaining how the mechanism of burning relates to the injury pattern and whether the injury is consistent with the history.

REVIEW METHODS

This review explores the robustness of the currently available evidence. The paper summarises the research from burn damage experimental work as well as bioheat transfer models and discusses the merits and limitations of these approaches.

REVIEW FINDINGS

There is broad agreement between in vitro and in vivo studies for superficial burns. There is clear evidence that the perception of pain in adult human skin occurs just above 43°C. When the basal layer of the epidermis reaches 44°C, burn injury occurs. For superficial dermal burns, the rate of tissue damage increases logarithmically with a linear increase in temperature. Beyond 70°C, rate of damage is so rapid that interpretation can be difficult. Depth of injury is also influenced by skin thickness, blood flow and cooling after injury. There is less clinical evidence for a time-temperature relationship for deep or subdermal burns. Bioheat transfer models are useful in research and becoming increasingly sophisticated but currently have limited practical use. Time-temperature relationships have not been established for burns in children's skin, although standards for domestic hot water suggest that the maximum temperature should be revised downward by 3-4°C to provide adequate burn protection for children.

CONCLUSION

Time-temperature relationships established for pain and superficial dermal burns in adult human skin have an extensive experimental modeling basis and reasonable clinical validation. However, time-temperature relationships for subdermal burns, full thickness burns and burn injury in children have limited clinical validation, being extrapolated from other data, and should be used with caution, particularly if presented during expert evidence.

Physiological and functional changes in the stratum corneum restored by oestrogen in an ovariectomized mice model of climacterium

Significant decreases in hormonal levels at menopause induce physiological and functional discomfort in the skin. Representative changes at menopause are based on so-called dry skin. However, there is no evidence to explain the mechanism, even though hydration of the stratum corneum (SC) in women at menopause is comparable with that at premenopause but is enhanced by hormone replacement therapy. This study objective was to evaluate structural and functional changes in the SC in ovariectomized mice model of menopause. Hydration of the SC, recovery of the permeability barrier function, integrity and cohesion of the SC, and irritant dermatitis were analysed in mice that underwent ovariectomy with or without replacement of 17ß-estradiol. In ovariectomized mice, hydration of the SC was reduced, recovery of permeability barrier function after acute disruption was impaired, and integrity of the SC was weakened and was associated with increased cohesion and increased levels of irritant dermatitis. Oestrogen replacement treatment restored all changes. Immunohistochemistry revealed reduced levels of expression of desmoglein-1 and differentiation markers of epidermis in ovariectomized mice compared with control mice and mice with oestrogen replacement treatment. These changes might be directly associated with weakened integrity and impaired permeability barrier function of the SC in ovariectomized mice. This study results reveal that so-called dry skin at menopause is caused by not only lower hydration of the SC but also complicated structural and functional changes in the SC and skin.

Epithelial-mesenchymal interaction mechanisms leading to the over-expression of neprilysin are involved in the UVB-induced formation of wrinkles in the skin

In clinical studies, the formation of facial wrinkles has been closely linked to the loss of elastic properties of the skin. Repetitive UVB irradiation of animal skin at suberythemal doses significantly reduces its elastic properties, resulting in the formation of wrinkles. That also elicits a marked alteration in the three-dimensional structure of elastic fibres, which is closely associated with a subsequent reduction in the elastic properties of the skin. While UVB irradiation stimulates the activity of skin fibroblast-derived elastase in the dermis, a synthetic inhibitor specific for skin fibroblast-derived elastase as well as an extract of Zingiber officinale (L.) Rose capable of inhibiting skin fibroblast-derived elastase, but not neutrophil elastase, prevented wrinkle formation in our studies of animal and human facial skin, respectively. The close interrelationship among wrinkle formation, elastic properties and elastic fibre linearity is revealed by the effects of different concentrations of the elastase inhibitor, which indicates that enhanced elastase activity by dermal fibroblasts plays a pivotal role in the UVB wrinkling mechanism. Fortunately, we were able to identify human skin fibroblast-derived elastase as the previously known enzyme neprilysin/neutral endopeptidase. Using both a UVB-conditioned medium assay and a co-culture system, we characterized the epithelial-mesenchymal interaction between keratinocytes and fibroblasts which leads to increased expression of neprilysin at the transcriptional, translational and enzymatic levels. Our results demonstrate that interleukin-1α and granulocyte-macrophage colony-stimulating factor are intrinsic cytokines secreted by UVB-exposed keratinocytes that stimulate the expression of neprilysin by skin fibroblasts.

Female rats are less susceptible during puberty to the lethal effects of percutaneous exposure to VX

Nerve agents with low volatility such as VX are primarily absorbed through the skin when released during combat or a terrorist attack. The barrier function of the stratum corneum may be compromised during certain stages of development, allowing VX to more easily penetrate through the skin. However, age-related differences in the lethal potency of VX have yet to be evaluated using the percutaneous (pc) route of exposure. Thus, we estimated the 24 and 48 h median lethal dose for pc exposure to VX in male and female rats during puberty and early adulthood. Pubescent, female rats were less susceptible than both their male and adult counterparts to the lethal effects associated with pc exposure to VX possibly because of hormonal changes during that stage of development. This study emphasizes the need to control for both age and sex when evaluating the toxicological effects associated with nerve agent exposure in the rat model.

Changes in Women's Facial Skin Color over the Ovulatory Cycle are Not Detectable by the Human Visual System

Human ovulation is not advertised, as it is in several primate species, by conspicuous sexual swellings. However, there is increasing evidence that the attractiveness of women's body odor, voice, and facial appearance peak during the fertile phase of their ovulatory cycle. Cycle effects on facial attractiveness may be underpinned by changes in facial skin color, but it is not clear if skin color varies cyclically in humans or if any changes are detectable. To test these questions we photographed women daily for at least one cycle. Changes in facial skin redness and luminance were then quantified by mapping the digital images to human long, medium, and shortwave visual receptors. We find cyclic variation in skin redness, but not luminance. Redness decreases rapidly after menstrual onset, increases in the days before ovulation, and remains high through the luteal phase. However, we also show that this variation is unlikely to be detectable by the human visual system. We conclude that changes in skin color are not responsible for the effects of the ovulatory cycle on women's attractiveness.

Biological mechanisms underlying the ultraviolet radiation-induced formation of skin wrinkling and sagging I: reduced skin elasticity, highly associated with enhanced dermal elastase activity, triggers wrinkling and sagging

The repetitive exposure of skin to ultraviolet B (UVB) preferentially elicits wrinkling while ultraviolet A (UVA) predominantly elicits sagging. In chronically UVB or UVA-exposed rat skin there is a similar tortuous deformation of elastic fibers together with decreased skin elasticity, whose magnitudes are greater in UVB-exposed skin than in UVA-exposed skin. Comparison of skin elasticity with the activity of matrix metalloproteinases (MMPs) in the dermis of ovariectomized rats after UVB or UVA irradiation demonstrates that skin elasticity is more significantly decreased in ovariectomized rats than in sham-operated rats, which is accompanied by a reciprocal increase in elastase activity but not in the activities of collagenases I or IV. Clinical studies using animal skin and human facial skin demonstrated that topical treatment with a specific inhibitor or an inhibitory extract of skin fibroblast-derived elastase distinctly attenuates UVB and sunlight-induced formation of wrinkling. Our results strongly indicated that the upregulated activity of skin fibroblast-derived elastase plays a pivotal role in wrinkling and/or sagging of the skin via the impairment of elastic fiber configuration and the subsequent loss of skin elasticity.

Estrogens induce rapid cytoskeleton re-organization in human dermal fibroblasts via the non-classical receptor GPR30

The post-menopausal decrease in estrogen circulating levels results in rapid skin deterioration pointing out to a protective effect exerted by these hormones. The identity of the skin cell type responding to estrogens is unclear as are the cellular and molecular processes they elicit. Here, we reported that lack of estrogens induces rapid re-organization of the human dermal fibroblast cytoskeleton resulting in striking cell shape change. This morphological change was accompanied by a spatial re-organization of focal adhesion and a substantial reduction of their number as evidenced by vinculin and actin co-staining. Cell morphology and cytoskeleton organization was fully restored upon 17β-estradiol (E2) addition. Treatment with specific ER antagonists and cycloheximide respectively showed that the E2 acts independently of the classical Estrogen Receptors and that cell shape change is mediated by non-genomic mechanisms. E2 treatment resulted in a rapid and transient activation of ERK1/2 but not Src or PI3K. We show that human fibroblasts express the non-classical E2 receptor GPR30 and that its agonist G-1 phenocopies the effect of E2. Inhibiting GPR30 through treatment with the G-15 antagonist or specific shRNA impaired E2 effects. Altogether, our data reveal a novel mechanism by which estrogens act on skin fibroblast by regulating cell shape through the non-classical G protein-coupled receptor GPR30 and ERK1/2 activation.

Stem cells and aberrant signaling of molecular systems in skin aging

The skin is the body's largest organ and it is able to self-repair throughout an individual's life. With advanced age, skin is prone to degenerate in response to damage. Although cosmetic surgery has been widely adopted to rejuvinate skin, we are far from a clear understanding of the mechanisms responsible for skin aging. Recently, adult skin-resident stem/progenitor cells, growth arrest, senescence or apoptotic death and dysfunction caused by alterations in key signaling genes, such as Ras/Raf/MEK/ERK, PI3K/Akt-kinases, Wnt, p21 and p53, have been shown to play a vital role in skin regeneration. Simultaneously, enhanced telomere attrition, hormone exhaustion, oxidative stress, genetic events and ultraviolet radiation exposure that result in severe DNA damage, genomic instability and epigenetic mutations also contribute to skin aging. Therefore, cell replacement and targeting of the molecular systems found in skin hold great promise for controlling or even curing skin aging.