Skin

An extremely well-preserved dinosaur ( Cf. Edmontosaurus sp.) found in the Hell Creek Formation (Upper Cretaceous, North Dakota) retains soft-tissue replacement structures and associated organic compounds. Mineral cements precipitated in the skin apparently follow original cell boundaries, partially preserving epidermis microstructure. Infrared and electron microprobe images of ossified tendon clearly show preserved mineral zonation, with silica and trapped carbon dioxide forming thin linings on Haversian canals within apatite. Furthermore, Fourier transform infrared spectroscopy (FTIR) of materials recovered from the skin and terminal ungual phalanx suggests the presence of compounds containing amide groups. Amino acid composition analyses of the mineralized skin envelope clearly differ from the surrounding matrix; however, intact proteins could not be obtained using protein mass spectrometry. The presence of endogenously derived organics from the skin was further demonstrated by p...

In the treatment of photoaged skin, glycolic acid works by removing superficial portions of the epidermis and stimulating dermis regeneration. Vitamins A, C, and E should stimulate collagen production and antioxidants should prevent free radical damage and skin aging. However, the effectiveness of different therapies has often relied on subjective methods of assessment. Histologic analysis has seldom been used because of the drawback of permanent scarring. In the literature, the use of a quantitative method for the assessment of facial rejuvenation has been described: the silicone replica technique. The authors' aim was to promote and recommend the use of this technique and, in particular, to test the effect of glycolic acid and multivitamin- and antioxidant-based products on skin texture. The authors performed a prospective, randomized, double-blind, controlled study on 30 women treated topically in the outer canthal region (crow's-feet area). Patients were divided into thr...

The South American lungfish, Lepidosiren paradoxa inhabits seasonal environments in the Central Amazon and Paraná-Paraguay basins that undergo significant oscillations in temperature throughout the year. They rely on different gas exchange organs, such as gills and skin for aquatic gas exchange while their truly bilateral lungs are responsible for aerial gas exchange; however, there are no data available on the individual contributions of the skin and the gills to total aquatic gas exchange in L. paradoxa. Thus, in the present study we quantify the relative contributions of skin and gills on total aquatic gas exchange during warm (35°C) and cold exposure (20°C) in addition to the effects of aerial and aquatic hypercarbia on aquatic gas exchange and gill ventilation rate (fG; 25°C), respectively. Elevated temperature (35°C) caused a significant increase in the contribution of cutaneous (from 0.61±0.13 to 1.34±0.26ml. STPD.h(-1)kg(-1)) and branchial (from 0.54±0.17 to 1.73±0.53ml. STP...

Senescence marker protein-30/gluconolactonase knockout mice (SMP-30/GNL-KO) are a very useful model for clarifying the involvement of vitamin C (VC) in aging-related diseases. In this study, the effects of VC deficiency on skin and hair growth were investigated using SMP-30/GNL-KO mice by RNA sequencing. SMP-30/GNL-KO mice were given water containing 1.5 g/l VC until up to 8 weeks after birth to maintain a VC concentration in their organs and plasma equivalent to that in wild-type mice. The mice were then divided into two groups: a VC(+) group, where VC was administered, and a VC(-) group, where VC was not administered. Skin samples were collected at 4 and 8 weeks after the treatment. RNA was extracted from each skin sample, followed by cDNA synthesis and RNA-seq. In addition, hair growth was compared between the VC(-) and VC(+) groups after shaving. Skin samples were collected from the shaved area for histological examination by hematoxylin & eosin (HE) staining. RNA-seq revealed t...

Acanthamoeba is a recognized pathogen in the immunocompromised patient, commonly presenting as chronic or subacute encephalitis. However, cutaneous disease in the absence of CNS involvement is increasingly recognized, especially in the setting of chronic, nonhealing skin lesions in the patient with AIDS. We describe a patient with AIDS and cutaneous acanthamoebiasis and review our experience with treatment and diagnosis.

The OECD guideline for studies on percutaneous penetration to be used in hazard and risk evaluations prescribes experimental conditions with optimal barrier integrity of the skin, which in many occupational settings probably is not true. Thus, workers may have compromised skin due to chemical or mechanical damage, due to different medical conditions (eczema, dermatitis, skin irritation) or related to occupational scenarios involving prolonged wet work. The present study used the OECD guideline procedures to study the in vitro percutaneous penetration through human skin of a number of model substances (glyphosat, caffeine, benzoic acid, malathion) covering a range of solubilities. Further, we studied the extent to which a slightly damaged skin would change the rate, the amount absorbed during dermal exposure and the distribution of chemical deposition between epidermis and dermis. The present study demonstrates that a limited damage to the skin significantly increases the permeability coefficient (K p) as well as total percutaneous penetration of chemicals, and most significantly for those compounds that due to their physicochemical characteristics (the most hydrophilic as well as the most lipophilic) have low penetration rates through intact skin. The present experiment not only confirms the proportionality between lipophilicity and potential for percutaneous penetration, but also illustrates that at a certain degree of lipophilicity of a model compound, the different skin compartments become more attractive for temporary deposition of model compounds. Moreover, a clear change from epidermal deposition towards a dominating dermis deposition of chemicals temporarily deposited within the skin is seen following damage to the skin barrier. Thus, the distribution of chemicals within the skin compartments is affected by the physicochemical characteristics of the chemicals as well as by the integrity of the skin. This observation may have implications when evaluating the possibility of removing chemicals from the skin through different cleansing procedures following unintended dermal exposures.

Surgical site infection (SSI) is one of the most frequent health care-associated infections. One of the practices to reduce their incidence is preoperative skin antisepsis. Two of the most commonly active components used are chlorhexidine gluconate and povidone iodine. Of 3 reviews conducted between 2010 and 2012 comparing antiseptics, 2 were in favor of chlorhexidine; however, the latest was unable to draw conclusions. To verify whether recent evidence supports the hypothesis that chlorhexidine in preoperative antisepsis is more efficient than other antiseptics in reducing SSI rates. We conducted a systematic review from 2000-2014 in all languages. The primary end point was SSI incidence and secondary skin bacterial colonization. Nineteen studies were included. Meta-analysis were conducted for comparable studies for both outcomes. The results of the meta-analysis, including all of the studies in which chlorhexidine was compared with iodophor, were in favor of chlorhexidine for both...

Chronic kidney disease (CKD) is associated with high morbidity and mortality rates, main causes related with cardiovascular disease (CVD) and bone mineral disorder (CKD-BMD). Uremic toxins, as advanced glycation end products (AGEs), are non-traditional cardiovascular risk factor and play a role on development of CKD-BMD in CKD. The measurement of skin autofluorescence (sAF) is a noninvasive method to assess the level of AGEs in tissue, validated in CKD patients. The aim of this study is analyze AGEs measured by sAF levels (AGEs-sAF) and its relations with CVD and BMD parameters in HD patients. Twenty prevalent HD patients (HD group) and healthy subjects (Control group, n = 24), performed biochemical tests and measurements of anthropometric parameters and AGEs-sAF. In addition, HD group performed measurement of intact parathormone (iPTH), transthoracic echocardiogram and radiographies of pelvis and hands for vascular calcification score. AGEs-sAF levels are elevated both in HD and co...

1. Frog integumentary mucins (FIM-A.1, FIM-B.1 and FIM-C.1) consist of typical threonine-rich highly O-glycosylated (semi)repetitive domains, and cysteine-rich modules, i.e. the P-domain, the short consensus repeat and a region with high similarity to the C-terminal end of von Willebrand factor (designated here CC29-motif). 2. These modules are thought to be involved in protein-protein interactions and they have been observed in a variety of extracellular proteins. In FIMs, these modules may be involved in oligomerization processes leading to an entangled mucin network. 3. Polydispersities have been detected in FIM-B.1 and FIM-C.1 within single individuals. Multiple transcripts are probably generated by alternative splicing of a huge array of different (semi)repetitive cassettes encoding the threonine-rich domains. 4. Furthermore, genetic polymorphism is observed between different individuals, probably due to allelic variations in the number of (semi)repetitive cassettes.

A diffusion model is presented to account for the disposition of chemicals applied to skin as transient exposures. Two conditions are considered that apply to the skin surface following the exposure period, which are applicable to chemicals exhibiting two extremes of chemical volatility. For one case, representing highly volatile compounds, the solution is generalized to apply to multiple transient exposures. For both cases, algebraic expressions are derived to calculate the total amount of chemical that penetrates the skin. The theory is applied to experimental measurements of the in vitro penetration of diethyl phthalate applied to hairless guinea pig (HGP) skin and silicone rubber membranes (SRMs) as transient exposures. The transient exposure theory ably models the experimental data, with coefficients of determination greater than 0.97 (HGP) and greater than 0.99 (SRM). The ability of parameters derived from concurrent infinite dose experiments to predict the time course of absorption from transient exposures is explored. Discrepancies were found between measured cumulative penetration of chemical from transient exposure experiments and penetration predicted from parameters derived from infinite dose experiments, particularly for HGP. Possible reasons are explored. The current model may provide a realistic framework for estimating absorption from occupational, environmental and pharmaceutical dermal exposures. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:1578–1592, 2008

Kyungohkgo (KOG) is one of the most important formulas in traditional oriental medicine. We investigated the remedial effect of KOG on the development of atopic dermatitis (AD) in female NC/Nga mice. AD-like lesion was induced by the application of 2,4-Dinitrochlorobenzene on to the back skin repeatedly; KOG was administered orally (12.5 and 25.0 mg/kg) and topically (0.5 and 1.0 mg/mouse) to NC/Nga mice once a day for all through the period of this experiment and every mouse body weight was periodically taken. The effects of KOG on 2,4-Dinitrochlorobenzene-treated NC/Nga mice were determined by measuring AD-like skin lesions, the infiltration of mast cells and serum immunoglobulin E concentration. After the KOG applications are over, the KOG groups had less skin lesions than the atopy one, their immunoglobulin E levels were significantly downregulated and the infiltration of mast cells in the dorsal skin were reduced. Our results suggest that KOG may be effective in alleviating the development of AD. The inhibition of AD in NC/Nga mice may be influenced by the prevention of mast cell activation.

The ethanol extract of the bark of Cinnamomum zeylanicum was evaluated for wound healing activity in Wistar rats. The extract was administered by the oral route at a dose of 250 mg/kg and 500 mg/kg body weight (1/8 and 1/4 of LD50, respectively) for all the wound models selected, excision, incision and dead space wounds. The extract significantly enhanced the wound breaking strength in the case of incision wound, the rate of wound contraction and the period of epithelization in the case of excision wound. The granulation tissue weight, its breaking strength and its hydroxyproline content was also increased by the extract in the dead space wound. Copyright © 2003 John Wiley & Sons, Ltd.