Inner Skin Layer Research Articles

Determination of Vitamin E (α-Tocopherol Acetate) on the Surface of Human Skin by IR Fourier-Transform Spectrometry and Study of Some Aspects of Its Transdermal Transfer

Possibilities of using FTIR spectrometry for determining organic substances on the surface of human skin and studying some aspects of the transdermal transfer of cosmetic products from the surface to the inner layers of skin were considered. Vitamin E as alpha-tocopherol acetate was selected as a cosmetic product under study. A procedure for determining changes in the concentration of vitamin E over time was proposed, sampling using standard tablets of potassium bromide was used, and a dependence illustrating a decrease in the concentration of the cosmetic product over time was obtained. It was shown that FTIR spectrometry can be used as a simple and rapid method for studying mechanisms of substance transfer and transdermal properties of the skin.

Building a ciliated epithelium: Transcriptional regulation and radial intercalation of multiciliated cells.

The epidermis of the Xenopus embryo has emerged as a powerful tool for studying the development of a ciliated epithelium. Interspersed throughout the epithelium are multiciliated cells (MCCs) with 100+ motile cilia that beat in a coordinated manner to generate fluid flow over the surface of the cell. MCCs are essential for various developmental processes and, furthermore, ciliary dysfunction is associated with numerous pathologies. Therefore, understanding the cellular mechanisms involved in establishing a ciliated epithelium are of particular interest. MCCs originate in the inner epithelial layer of Xenopus skin, where Notch signaling plays a critical role in determining which progenitors will adopt a ciliated cell fate. Then, activation of various transcriptional regulators, such as GemC1 and MCIDAS, initiate the MCC transcriptional program, resulting in centriole amplification and the formation of motile cilia. Following specification and differentiation, MCCs undergo the process of radial intercalation, where cells apically migrate from the inner layer to the outer epithelial layer. This process involves the cooperation of various cytoskeletal networks, activation of various signaling molecules, and changes in cell-ECM and cell-cell adhesion. Coordination of these cellular processes is required for complete incorporation into the outer epithelial layer and generation of a functional ciliated epithelium. Here, we highlight recent advances made in understanding the transcriptional cascades required for MCC specification and differentiation and the coordination of cellular processes that facilitate radial intercalation. Proper regulation of these signaling pathways and processes are the foundation for developing a ciliated epithelium.

Study on reduction mechanism of Fe2O3 by NH3 under SNCR condition

Amino compounds were injected into a boiler at high-temperature area usually to realized De-NOx. However, amino compounds were highly corrosive. The metal tube skin of stage III superheater in a medium temperature separation circulating fluidized bed boiler (MTS-CFBB) was investigated to verify the corrosion effect of amino compounds on the boiler tube wall. The sodium salt which was found in the inner layer of the metal tube skin indicated that large area cracking occurred at the metal tube during the operation process; and further indicated that the corrosion rate of the tube wall was speedy. Meanwhile, the tube furnace experimental system and the reaction equations module in HSC Chemistry 6.0 were used to obtain the reduction properties of NH3 on Fe2O3 at high temperature. The weight loss rate of Fe2O3 under N2-NH3 atmosphere increased from 3.3 wt% to 5.5 wt%, when the temperature rose from 600 °C to 900 °C, and the weight loss rate of samples did not increase any more with the temperature rising to 1000 °C. The injected NH3 reduced the Fe3O4 to form FeO quickly at 810 °C. With the thermal stress caused by the boiler load adjustment and start up or shut down, the looser FeO formed at the interior of tubes, and then, the different expansion coefficient of Fe based compounds led to the extensive cracking. In summary, NH3 generated by SNCR was the main reason for corrosion happened on the tubes at high-temperature.

Hardware Implementation of Palm Vein Biometric Modality for Access Control in Multilayered Security System

Among the biometric modalities palm veins are the most secure and difficult to duplicate. This palm vein verification system aims to recognize a person from its exclusive palm vein organization that cannot be forged easily since veins are situated in inner layers of skin. Embedded devices are gaining increased attention in biometrics due to reliability and cost efficient systems. An embedded palm vein recognition system is the need of today in institutes, industries, security places etc. The aim of this proposed work is to implement palm vein identification system on hardware unit so that it can be further build into a single standalone unit, where it can be used in final level security in multilayered security system without any possibility of hacking. The hardware platform used in the proposed work is Blackfin ADSP-561 processor and the algorithms used for matching of palm vein are performed using C language. The project focuses on storing images and implementing the matching algorithms on hardware platform itself such that PC or laptop is not needed for identification purpose. Principal component analysis (PCA) and template matching techniques are used as verification algorithms of palm veins. Finally, it can be concluded from the experimental results that this approach can verify an individual with an average accuracy of 92%.

Evolutionarily conserved expression pattern and trans-regulating activity of Xenopus p51/p63

p51/p63, a member of the p53 gene family, is structurally conserved among a wide range of organisms, although the transactivator (TA) and N-terminally truncated (ΔN) isotype producing property seems to vary. Since p51/p63 is thought to play important roles in skin, limb, and craniofacial development in mammals, we examined Xenopus laevis larval and adult tissues for expression of p51/p63. Temporal analyses indicated enhanced transcription of the ΔN form of p51/p63 in premetamorphosis phase (at stage 44–48). p51/p63-positive cells in the inner layer of larval skin expanded to the suprabasal layers during the stratification. The epithelium of limb buds and the maxillofacial ectodermal tissues in tadpoles had a high level expression of p51/p63. The cloned ΔN-A/γ type Xenopus p51/p63 exhibited a dominant-negative activity against the human TA-A/γ isotype in a reporter assay. These results suggest that tissue-specific p51/p63-inducing mechanism and isotype-specific transcriptional regulator activities of p51/p63 are conserved between mammals and frogs.

Human skin basement membrane in health and in autoimmune diseases.

Skin basement membrane zone (BMZ) is an ultrastructurally defined area situated between the outer layer of skin, the epidermis, and the inner layer of skin, the dermis. The major function of skin BMZ is to serve as an adherent connection between the epidermis and the dermis. Heritable skin diseases characterized by genetic mutations that result in defective BMZ protein production, such as junctional and dystrophic epidermolysis bullosa, manifest clinically as skin fragility and subepidermal blister formation inducible by minor trauma. Many distinct, yet interconnected BMZ components, have been identified and studied extensively. Some of these essential components, interestingly, were discovered because they were targeted by an autoimmune reaction. As a result of studying the autoimmune diseases, these BMZ components involved in autoimmune reaction, or autoantigens, were isolated by molecular biology techniques. The isolation of these autoantigens, in turn, facilitates our studies of the normal structures and functions of skin BMZ. The skin BMZ can be divided into four ultrastructurally distinct areas: the hemidesmosome/upper lamina lucida, the lower lamina lucida, the lamina densa, and the sub-lamina densa. Well-characterized BMZ components include the hemidesmosome/upper lamina lucida-located bullous pemphigoid antigens (BP230 and BP180), a 6b4 integrin, and plectin; the lower lamina lucida-located laminin-1, laminin-5 (previously named kalinin, epiligrin, nicein, BM600), laminin-6 (previously named k-laminin), p105, and entactin/nidogen; the lamina densa-located type IV collagen and perlecan; and the sub-lamina densa-located type VII collagen (epidermolysis bullosa acquisita antigen). Mucosal BMZ also contain identical components as skin BMZ. Autoantibodies targeting skin and/or mucosal BMZ components, like that of genetic mutation of BMZ components, result in a histopathologically defined subepidermal blistering disease, that is, a blister which occurs just below the epidermis/epithelium. Well-characterized autoimmune subepidermal blistering diseases include bullous pemphigoid (BP), linear IgA bullous dermatosis, cicatricial pemphigoid (with subsets of patients characterized by autoantibodies targeting either BP antigens or laminins), anti-p105 pemphigoid, and epidermolysis bullosa acquisita. Using a simple method of direct or indirect immunofluorescence testing on a skin section chemically separated at the middle portion of lamina lucida, in combination with immunoelectron microscopy and target antigen determination, accurate diagnoses for various autoimmune subepidermal blistering diseases can be obtained.

In vitro penetration of tritium-labelled water (THO) and [ 3H]PbTx-3 (a red tide toxin) through monkey buccal mucosa and skin

The permeability coefficients ( K p) for tritium-labelled water (THO) were determined in human and monkey skin, and monkey buccal mucosa. K p of human skin (0.47 × 10 −3 cm/h) correlated favorably with previous reports. K p of hydrated monkey skin for THO (0.77 × 10 −3 cm/h) was not significantly different (P > 0.05) from K p of hydrated human skin (0.88 × 10 −3 cm/h). K p of monkey buccal mucosa for THO (6.15 × 10 −3 cm/h) was significantly greater than that for monkey skin. Penetration and disposition of [ 3H]PbTx-3 into layers of monkey buccal mucosa and skin was determined. [ 3H]PbTx-3 (5–7 μCi) dissolved in 2 ml of water was applied to epithelial/epidermal surface (2.8 cm 2) at zero time. The relative percent dose recovered from the upper layers of buccal mucosa (epithelium) and skin (epidermis) varied, but at each time interval was less than 2.5% of the dose. At most of the time intervals (2–24h), a larger percent of the dose was recovered from the inner layer of the buccal mucosa (lamina propria) than from the inner layer of skin (dermis). After 24 h, as much as 34 or 13% of the dose was recovered from lamina propria or dermis, respectively. At each time interval studied, less than 2% of dose of [ 3H]PbTx-3 penetrated into the receptor fluid which bathed the inner surfaces of the lamina propria or dermis. The results of this study demonstrate that monkey buccal mucosa is more permeable than skin to THO and PbTx-3

Increased transglutaminase activity during skin wound healing in rats

Outer, middle and inner layers from wounded or unwounded rat dorsal skin were separated and extracted first with buffer and then with Triton X-100 and dithiothreitol. The extracts and residues were assayed for transglutaminase activity and tissue transglutaminase antigen. Transglutaminase activities in all skin layers are increased in the period 1–5 days after wounding. Most of the increased activity is in the buffer-soluble fraction in the inner skin layer though there is no corresponding increase in antigen in this fraction. This suggests that there is production of activated soluble tissue transglutaminase in the wounded inner layer. In the 3–5-day wounded outer layer the largest fraction of both activity and antigen is associated with the insoluble residue remaining after extraction with Triton X-100. On DEAE-cellulose chromatography Triton X-100 extracts of the inner layer of wounded skin showed a single major peak of activity, corresponding approximately with rabbit liver transglutaminase; the outer layer showed the same peak plus a different one, eluting at lower salt concentration, which is thought to be epidermal transglutaminase.

Malathion binding to sections of human skin: skin capacity and isotherm determinations.

Human autopsy skin was sliced into three sections: an outer epidermis-rich layer, a middle dermis layer, and an inner dermis and subcutaneous fat layer. Each skin slice was bathed in malathion solutions over a 100-fold concentration range of 0.02-3.0 microM/g skin for 48 h at 37 degrees C. Malathion uptake approximated 50% for each skin layer over the total concentration range. Skin capacity for malathion is thus large. Single and double compartment dialysis was used to determine free and bound malathion. Isotherm calculations gave a partition coefficient intercept for epidermis-rich and dermis tissues with aqueous buffer of 2.72 and 2.74, respectively. That of the inner layer of skin was less at 1.70. When malathion was dialyzed against simulated plasma, the binding decreased 2-fold. Since the least partition coefficient (less bound malathion) was in the inner layer of skin, and since malathion has a preference for plasma over water, the two (inner skin and plasma) may combine to create the sink conditions necessary for malathion percutaneous absorption into the body.