Decreased expression of GPC1 in human skin keratinocytes and epidermis during ageing.

BACKGROUND: Glypicans (GPCs) are heparan sulfate cell membrane proteoglycans containing glycosylphosphatidylinositol (GPI) anchor. They play important role in cell behavior by activating/presenting numerous growth factors and cytokines. OBJECTIVES: The expression of GPCs was investigated in primary culture of skin keratinocytes sampled from healthy donors of different age. MATERIALS AND METHODS: Primary keratinocytes from healthy female donors aged from 20 to 89 years old (n = 30) were either isolated from breast or abdominal skin samples (n = 27) or purchased (n = 3). GPCs expression was examined by qPCR, immunohistochemistry and western blot. Its role in proliferation induced by fibroblast growth factor 2 (FGF2) was also studied. RESULTS: Glypican 1 (GPC1) was the major expressed GPC in human keratinocytes. Its expression was up to two orders of magnitude higher than other GPCs and was significantly decreased with the age of the donors. It was localized at the cell surface and associated with intracellular granules. In skin sections, GPC1 was mainly localized in basal layer of epidermis. Shedding of GPCs decreased the proliferative effect of FGF2, confirming their role of modulator of growth factor effects on keratinocytes. These results established GPC1 as an important player in epidermis biology and skin ageing.

SkinExplorer: a new high-tech platform to interact inside the skin by immersive virtual 3D cutaneous environment.

BACKGROUND: The confocal laser scanning microscope allows performing acquisition of several histological sections with precise visual morphological landmarks and their reconstruction. A powerful and modern confocal microscope enables to quickly reconstruct virtual 3D models. OBJECTIVE: The main goal was to develop a new platform to reconstruct complex mosaic serial data, interact with it in an immersive 3D environment, and give to the observers a feeling of 'presence' inside the skin. METHOD: We have developed novel methods that transform the data into alternative representation, well-suited to explore cutaneous structures in detail and to observe fields of data from different points of view. This new way of data reconstruction in volume requires optimization of intensities, automatic matching algorithms and depth alignment. RESULTS AND CONCLUSION: The new platform - SkinExplorer evolves as a 3D exploration prototype. This technology provides an immersive virtual environment to explore cutaneous microstructures. Several serial histological sections can be matched by stacks, aligned in depth by sections and merged together to be visualized as a whole. All these time-consuming steps have been dramatically speed-up using rapid image processing. The advantages of using virtual reality technologies such as the ones used in the SkinExplorer platform are automatic matching, precise alignment, better data perception, lower memory requirement, and higher quantity of simultaneously displayed data. This platform can render volumetric data and isosurfaces, separately or both at the same time. Lighting and depth perception are enhanced using 'Sphere Mapping', 'Ambient Occlusion', and 'Halo' methods when displaying iso-surfacic volume models with high complexity depth. The assets of the platform are to interpret complex three-dimensional data, to observe and explore 3D virtual models, and to show effects of cosmetic treatments.

Glycation during human dermal intrinsic and actinic ageing: an in vivo and in vitro model study.

BACKGROUND: Non-enzymatic glycation occurring in normal human skin plays an important part in ageing. OBJECTIVES To visualize and quantify, in human subjects, the extent of glycation during human dermal intrinsic and actinic ageing, and to develop a reliable reproducible in vitro model for evaluating the efficacy of potential inhibitors of glycation. METHODS: By immunohistochemistry using a monoclonal antibody recognizing carboxymethyl lysine, an advanced glycation end-product (AGE) (first objective), and by incubating dead de-epidermized dermis (DED) with glucose to simulate ageing-induced glycation in a human dermal equivalent model (second objective). RESULTS: We found that glycation of the dermis generally arises after 35 years, then increases rapidly with intrinsic ageing. We also noticed an enhancement of glycation by solar irradiation that occurred via glycation of the elastic fibre network or solar elastosis tissue. In the model, production of AGEs appeared in a time-dependent way, mimicking glycation observed in vivo during chronological ageing. Irradiation of DED before incubation with glucose strongly enhanced induction of AGEs, corresponding to the effect of solar irradiation on AGEs observed in vivo. CONCLUSIONS: These results confirm a marked increase of AGEs during intrinsic ageing in normal human skin and also suggest that glycation is enhanced in photoaged skin.

A histological study of human wrinkle structures: comparison between sun-exposed areas of the face, with or without wrinkles, and sun-protected areas.

Wrinkles are a major topic in dermocosmetology; the purpose of this work has been to go deeper into the knowledge of cutaneous damage underlying these modifications of skin surface. Up to now, the number of published works about the histological structure of wrinkles is not very large. Therefore to complete the findings, we studied 46 subjects of both sexes, between 57 and 98-year-old, enabling us to obtain 157 skin biopsies of wrinkles (face) and sun-protected areas (abdomen). We used different histological techniques involving histochemistry, immunohistochemistry, electron microscopy and quantification by image analysis in addition to classic standard techniques. This study has allowed us to confirm published structural modifications of wrinkles, but also to display many other original alterations. The increased thinning of the epidermis atrophied with age is confirmed by the study of desmoplakins outlining the cellular contours of keratinocytes. Such a thinning is accompanied by a decrease in several markers of epidermal differentiation at the bottom of the wrinkles: filaggrin, keratohyalin granules and transglutaminase I, disturbing desquamation and the capacity of the horny layer to retain water. The dermoepidermal junction is modified by a decrease of collagen IV and VII, which, combined with fewer and fewer oxytalan fibres under wrinkles, weakens this interface. The deposition of abnormal elastotic tissue in the dermis, with an interruption of these deposits under wrinkles and an atrophy of dermal collagen more pronounced under wrinkles, boosts the magnitude and depth of wrinkles. The composition of the other dermal constituents is also altered with, more particularly, a marked decrease of chondroitin sulphates in the papillary dermis under wrinkles, combined with an asymmetrical variation of glycosaminoglycans on both edges of wrinkles. The atrophy of the hypodermis, also more marked under wrinkles, with a thickening of fibrous lines, also makes the depth of wrinkles more pronounced. Wrinkle formation appears at the same time as numerous modifications in different cutaneous structures, which may be mutually amplified. Such a study by pointing out altered elements in skin physiology, makes the development of specific treatments possible in order to mitigate this unwelcome cutaneous deterioration.

Epidemiological experience in the mission of the United Nations Transition Assistance Group (UNTAG) in Namibia.

Epidemiological data have rarely been generated during United Nations (UN) missions to Third World countries, even in situations where there is hardly any combat involvement. Continuous surveillance was therefore carried out during the 12-month stay of UN personnel in Namibia in 1989-90. In this population of 7114 persons, mostly young men, the mortality rate was 255 per 100,000; death was mainly due to traffic accidents. Hospitalization was chiefly because of fever of unknown origin or trauma. Repatriation to the country of origin was necessary in 46 patients, frequently for psychiatric reasons including alcoholism. Over this one-year period there were, on average, 2.7 new consultations per person for treatment (mostly for dental problems), and 0.8 per person for prophylactic measures. The extremely high mortality due to traffic accidents indicates a need for prevention. In the selection process for future missions, more emphasis should be given to the psychological and dental health of volunteers. All military contingents and civilian groups should learn about effective preventive measures prior to their arrival, and adhere to them.

PIP: Medical reports modelled after the US Peace Corps surveillance form provided mortality and morbidity data of the United Nations Transition Assistance Group in Namibia in 1989-1990. Contingents included Australians, Canadians, Danes, Finns, Kenyans, Malays, Poles, Spaniards, and Britons. Traffic accidents, mostly those on long distance journeys caused 14 of 16 deaths. The fatality ratio was 0.21/million km driven which was considerably higher than that in Switzerland 0.02/million km driven. Even though heavy traffic was not a problem in Namibia, limited experience on unpaved roads; high speeds induced by long and tedious driving; and reduced visibility caused by climactic conditions, fatigue, and alcohol contributed to high fatality. The hospitalization rate of 5.2% (369 patients) was rather high for a young and healthy population. The leading reasons for hospitalization included fever of unknown origin, trauma, and respiratory tract infections. Swiss Medical Unit physicians transferred 25 patients to the State Hospital in Windhoek, most for orthopedic surgery. Injuries, psychiatric problems, and alcoholism resulted in repatriation for 66% of 46 repatriated patients. New consultations for treatment averaged 2.7/person and those for preventive measures averaged 0.8/person. Helicopter pilots was the largest group returning for 2nd visits (56% compared to 1% for logistics staff). The major reasons for attending outpatient clinics included immunizations (18.8%), dental problems (10.5%), and respiratory infections (10.5%). In addition to respiratory infections, other frequent communicable diseases included diarrhea or dysentery, dermatological infections, sexually transmitted diseases, and confirmed or suspected malaria. Preventive measures are needed to reduce mortality due to traffic accidents and the prevalence of psychological and dental problems.