Improved Barrier Structure Formation in Air-Exposed Human Keratinocyte Culture Systems

The epidermis (including stratum corneum) of human keratinocytes cultured at the air-liquid interface attached to an appropriate substrate shows a morphology closely mimicking that of its in vivo counterpart. In spite of the histologic similarities, the barrier function seems to be impaired. The aim of the present study was to characterize development and structure of the epidermal permeability barrier in two human skin recombinants using electron microscopy (including ruthenium tetroxide-post fixation technique) and analysis of lipid composition. The epidermis was reconstructed by growing human keratinocytes either on de-epidermized dermis or on a bovine collagen-containing matrix with active fibroblasts (Living Skin Equivalent). Ultrastructurally both culture systems showed a) an abnormal lamellar body delivery system, b) disturbance of transformation into lamellar lipid bilayers, c) an impaired structural organization and distribution of the epidermal lipids in the intercellular spaces. In either of the systems used, prolongation of the culture period did not induce any significant improvement in the stratum corneum lipid organization. Whereas the Living Skin Equivalent showed only sparse lamellar bodies, the number of lamellar bodies in the human keratinocyte culture on de-epidermized dermis grown in regular medium seemed to be comparable to native skin. Contrary to the Living Skin Equivalent, the keratinocyte culture on de-epidermized dermis contained a higher number of intracorneocytic lipid droplets correlating with a higher triglyceride content in the lipid analyses. By reconstructing the keratinocyte culture on de-epidermized dermis with the same medium as used for the Living Skin Equivalent, both lipid composition (lower triglyceride, higher ceramide contents) and structural organization were improved, and regular lamellar lipid bilayers comparable to those of native skin appeared

Sun safety knowledge and practice in UK postal delivery workers

Background: Postal delivery workers spend a large proportion of their work time outdoors, placing them at increased risk for skin cancer. To date, no studies have examined occupational sun safety knowledge and practice within this group in the UK. Aims: To describe the occupational sun safety knowledge and practice of UK postal delivery workers and to investigate the association of demographic, personal and occupational factors with knowledge and practice in order to identify potential strategies for improving sun safety in this occupational group. Methods: Postal delivery workers completed a questionnaire that collected data on occupational sun safety knowledge and practice in addition to demographic, personal and workplace characteristics. One-way analysis of variances were applied to assess differences in knowledge and practice by these characteristics. Results: A total of 1153 postal delivery workers completed the questionnaire, a 60% response rate. Thirty three per cent reported receiving sun safety training within the previous 12 months. The majority of respondents reported correct knowledge on three of the six domains and good practice on four of the six behavioural domains. However, only one-fifth of respondents reported wearing sunglasses and ensuring a plentiful intake of water. Knowledge and practice differed significantly according to demographic, personal and workplace characteristics. Conclusions: There is a need to raise the profile of occupational skin cancer in this occupational group and to increase the priority given to occupational sun safety policies alongside targeted and tailored interventions, the effect of which can be evaluated

Галльский пласт в современном немецком литературном языке: структурно-системный и функционально-динамический аспекты

Диссертационное исследование Меремкуловой Татьяны Игоревны выполнено в русле контактной лингвистики, стремительно развивающейся ветви исторического языкознания, и посвящено определению структурно-системных и функционально-динамических характеристик заимствованных лексических единиц галльского пласта в системе современного немецкого литературного языка и в синхронной немецкой литературной речи.The dissertation research of Meremkulova Tatyana Igorevna is carried out in the mainstream of the contact linguistics, the rapidly developing branch of historical linguistics, and is devoted to the determination of structural-systemic and functional-dynamic characteristics of the borrowed lexical units of the Gallic layer in the system of modern German literary language and in synchronous German literary speech

Cosmeceuticals based on Rhealba® Oat plantlet extract for the treatment of acne vulgaris

Recent evidence suggests that acne vulgaris begins as an inflammation in and around the sebaceous gland and alterations in the lipid content of sebum, which drive hyperproliferation and increased desquamation of keratinocytes within sebaceous follicles. This prevents sebum drainage, causing the formation of microcomedones, which spontaneously regress or become acne lesions when the pilosebaceous unit is further blocked by the accumulation of corneocytes. These conditions are favourable for the proliferation of Propionibacterium acnes, which further aggravates acne by enhancing abnormal desquamation, sebum production and inflammation. Also, skin fragility due to inflammation or irritation by anti-comedogenic agents can worsen the situation. Rhealba((R)) Oat plantlet extract (Pierre Fabre Dermo Cosmetique) soothes and restores fragile skin in acne by reducing inflammation and inhibits bacterial adhesion of Propionibacterium acnes. Cosmeceuticals combining Rhealba((R)) Oat plantlet extract and hydro-compensating actives, which are available with or without anti-comedogenic hydroxy acids, provide a balanced, multifaceted approach for acne patients

Photocrosslinkable gelatin hydrogel for epidermal tissue engineering

Natural hydrogels are promising scaffolds to engineer epidermis. Currently, natural hydrogels used to support epidermal regeneration are mainly collagen- or gelatin-based, which mimic the natural dermal extracellular matrix but often suffer from insufficient and uncontrollable mechanical and degradation properties. In this study, a photocrosslinkable gelatin (i.e., gelatin methacrylamide (GelMA)) with tunable mechanical, degradation, and biological properties is used to engineer the epidermis for skin tissue engineering applications. The results reveal that the mechanical and degradation properties of the developed hydrogels can be readily modified by varying the hydrogel concentration, with elastic and compressive moduli tuned from a few kPa to a few hundred kPa, and the degradation times varied from a few days to several months. Additionally, hydrogels of all concentrations displayed excellent cell viability (>90%) with increasing cell adhesion and proliferation corresponding to increases in hydrogel concentrations. Furthermore, the hydrogels are found to support keratinocyte growth, differentiation, and stratification into a reconstructed multilayered epidermis with adequate barrier functions. The robust and tunable properties of GelMA hydrogels suggest that the keratinocyte laden hydrogels can be used as epidermal substitutes, wound dressings, or substrates to construct various in vitro skin models

Влияние недропользования на социально-экономическое развитие Томской области

Анализ влияния деятельности нефтегазового комплекса на социально-экономическое развитие Томской области.Analysis of the impact of the oil and gas industry on the social and economic development of the Tomsk region

In Vivo Methods for the Assessment of Topical Drug Bioavailability

This paper reviews some current methods for the in vivo assessment of local cutaneous bioavailability in humans after topical drug application. After an introduction discussing the importance of local drug bioavailability assessment and the limitations of model-based predictions, the focus turns to the relevance of experimental studies. The available techniques are then reviewed in detail, with particular emphasis on the tape stripping and microdialysis methodologies. Other less developed techniques, including the skin biopsy, suction blister, follicle removal and confocal Raman spectroscopy techniques are also described