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With the availability of the local lymph node assay, and the ability to evaluate effectively the relative skin sensitizing potency of contact allergens, a model for quantitative-risk-assessment (QRA) has been developed. This QRA process comprises: (a) determination of a no-expected-sensitisation-induction-level (NESIL), (b) incorporation of sensitization-assessment-factors (SAFs) reflecting variations between subjects, product use patterns and matrices, and (c) estimation of consumer-exposure-level (CEL). Based on these elements an acceptable-exposure-level (AEL) can be calculated by dividing the NESIL of the product by individual SAFs. Finally, the AEL is compared with the CEL to judge about risks to human health. We propose a simplified approach to risk assessment of hair dye ingredients by making use of precise experimental product exposure data. This data set provides firmly established dose/unit area concentrations under relevant consumer use conditions referred to as the measured-exposure-level (MEL). For that reason a direct comparison is possible between the NESIL with the MEL as a proof-of-concept quantification of the risk of skin sensitization. This is illustrated here by reference to two specific hair dye ingredients p-phenylenediamine and resorcinol. Comparison of these robust and toxicologically relevant values is therefore considered an improvement versus a hazard-based classification of hair dye ingredients. (C) 2012 Elsevier Inc. All rights reserved

Estimating tourism demand has become a challenge among researchers, as identification of key determinants is important for policymakers at a time when tourism has become the world's largest industry. Using a theoretical framework based on the gravity model, this paper models inbound tourism demand for South Africa to estimate price and income sensitivities as well as the impact of other important factors that affect tourist flows, such as the location of markets and socio-political factors. Given the non-stationary but cointegrated nature of the panel data, panel cointegration estimation techniques are employed. The results show that tourists are sensitive to price changes in South Africa and also to tourism price changes in competing destinations. The level of development, tourism infrastructure, distance (or transportation costs), common border and language are also found to affect arrivals. The results also indicate the need to conduct estimation by regional groupings for a better understanding of different markets.

This article models inbound tourism demand for South Africa using a theoretical framework that is based on the gravity model and provides elasticity estimates that are useful for policy purposes. It uses a well-established gravity model following Anderson and van Wincoop's model (2003) to explain tourism flows. The article departs from most of the existing work estimating tourism demand and builds on the recent work of Durbarry, but employs a dynamic panel data setting. The results show that tourists are not too sensitive to changes in the tourism price of South Africa, indicating that it offers a unique product and experience to tourists. In fact, evidence tends to suggest that competing destinations may imploy tourism products that are unique to their destinations in the region. The level of development and tourism infrastructure also affect arrivals. It is also found that distance negatively affects arrivals, but common border and language play an important role. The dynamic model supports the presence of repeat tourism and positive word-of-mouth, particularly from European and American origins.

Resume Objectifs La projection accidentelle d’un produit detergent et desinfectant ou d’un savon antiseptique sur les pieds peut etre responsable d’une dermatite irritative aigue allant du simple erytheme a la brulure caustique. Le risque de cette lesion cutanee est de favoriser une sensibilisation, en particulier aux composants des chaussures, notamment en cuir. L’interet de notre travail est de souligner l’importance de declarer tout fait accidentel survenant sur le lieu de travail. Methode Nous rapportons l’histoire clinique de deux patientes, l’une infirmiere hospitaliere, l’autre agent de service dans une maison de retraite, qui ont developpe une allergie de contact aux chaussures, secondaire a une dermatite caustique contractee en service. Des tests epicutanes sont realises afin d’identifier le ou les allergenes en cause. Resultats L’exploration allergologique a confirme la sensibilisation a plusieurs ingredients entrant dans la composition des chaussures, parmi lesquels le bichromate de potassium, la resine para-tertiaire-butylphenol formaldehyde et la colophane, allergenes non presents au travail. Conclusion L’eviction des allergenes est indispensable pour obtenir la guerison des lesions et prevenir les recidives. D’un point de vue medico-legal et professionnel, une sensibilisation a un allergene sans relation directe avec le travail, mais secondaire a une lesion imputable au service, ne permet pas une reconnaissance en maladie professionnelle. En revanche, la possibilite d’une requalification en accident de service ou de travail des lesions initiales des pieds permettrait une meilleure indemnisation.

Synopsis Antielastase activity of derivatives like ‘propionylaminoacid’(C3 prolin, C3 hydroxyprolin, C3 collagen) was examined for pancreatic elastase, and fibroblastic elastase production. Essential metabolic variations of normal dermal fibroblasts were evaluated: adhesion, proliferation capacity, total protein biosynthesis and collagen type I and type III production. Possible other factors such as cellular nutrients were examined by oxygen consumption evaluation. Propionylaminoacid derivatives have antielastase activities. Pancreatic elastase showed dose related inhibition (20% to 50% inhibition for concentration from 5 to 80 mg ml−1. Moreover, fibroblastic elastase production was inhibited, cellular respiration was enhanced. A very good tolerance in vitro was observed for concentration 0–1 mg ml−1 range: adhesion, proliferation capacity and collagen (type I and type III) production were not altered, and oxygen consumption was enhanced. Resume Les auteurs ont etudie l'activite antielastasique de trois derives du type propionylaminoacide: C3 proline, C3 hydroxyproline, C3 collagene, en presence d'elastase pancreatique mais aussi vis a vis de la production de l'elastase fibroblastique. Par ailleurs, ils ont examine les possibles modifications des parametres metaboliques essentiels des fibroblastes dermiques humains normaux a savoir: l'adhesion, la proliferation, le niveau de biosynthese des proteines totales, la production de collagene de type I et III. Enfin ils ont recherche une eventuelle activite en tant que nutriment cellulaire par evaluation de l'augmentation de la consommation d'oxygene. Les derives propionylaminoacide etudies sont tres fortement antielastasiques. Ils inhibent l'elastase pancreatique de facon dose-dependante de 20 a 50% pour des concentrations variant de 0.5 a 8%. Ils inhibent en outre la production d'elastase fibroblastique. On peut considerer qu'ils presentent une excellente tolerance in vitroa des concentrations elevees de l'ordre du mg ml-1 puisqu'ils ne modifient pas les autres parametres du metabolisme fibroblastique tels que l'adhesion, la proliferation et la production de collagene de type I et III. En revanche ils provoquent une nette stimulation de la respiration cellulaire.

Les virus de leucemie murine sont transcriptionnellement inactifs dans les cellules embryonnaires ou ils est soumis a plusieurs mecanismes de controle negatif. Cependant, dans de tres rares cas, ces virus peuvent etre integres a une unite de transcription cellulaire active et exprimes dans les cellules indifferenciees. Un transcrit hybride commencant au debut d'un gene cellulaire se poursuit dans l'ADN proviral et est episse en utilisant un site accepteur cryptique du virus. Un tel mecanisme pourrait aboutir a l'annexion par un retrovirus de sequences cellulaires en aval desquelles il est integre

The inhibitor of DNA-methylation, 5-azacytidine (5- AzaC ) induced the appearance of cytokeratin-containing cells in several mesenchymal cell lines such as teratocarcinoma-derived fibroblasts, preadipocytes and myoblasts, NIH-3T3 fibroblasts and human embryonic fibroblasts. At optimal 5- AzaC concentrations the proportion of such cells was in the range of 10(-1) compared with 10(-6) -10(-4) in non-treated cultures. Dose-response curves indicated that the induction of cytokeratin was the result of an interaction of the drug with few targets. Stable, mature, keratinocyte cell lines, as well as lines of myoblasts and astrocytes, could be isolated from a teratocarcinoma-derived preadipocyte line, showing that 5- AzaC is able to provoke a wide range of complete phenotypic conversions. In these cell lines, the intermediate filaments corresponded to the morphological phenotype. Altogether, the results suggest that 5- AzaC preferentially activates certain genes.

T lymphocyte maturation activity of supernatants from cultured human epidermal cells was investigated using a biological rosette assay based upon Thy 1 induction on T cell precursors. Between days 5 and 18 of keratinocyte cultures, supernatants exhibited Thy 1-inductive properties. Optimal activity was found between days 10 and 14 of culture, which correspond to the beginning of epidermal cell stratification. This activity was independent of the presence of prostaglandin E. Absorption experiments using monoclonal and polyclonal antibodies showed that ELDIF was different from other recognized thymic hormones (thymulin, thymopoietin, thymosin α1), produced by thymic epithelial cells and known to induce T cell markers.

Resume Une proteine-kinase et une pppA(2′p5′A)n-synthetase (2-5A-synthetase) dependantes de l'ARN bicatenaire sont induites dans les cellules traitees par l'interferon. Le niveau de ces enzymes est egalement augmente dans des cellules infectees par un virus (et donc produisant de l'interferon) telles que les cellules de souris L929 infectees par le virus de la maladie de Newcastle. Les cellules infectees en presence de haute concentration de globulines anti-interferon, ne montrent pas une augmentation de la proteine-kinase et de la 2-5A-synthetase. En utilisant des cellules de carcinome embryonnaire de souris qui sont incapables de produire de l'interferon, nous avons observe que l'infection virale ne modifie pas le niveau de ces deux enzymes. Par consequent, l'augmentation des activites de la proteine-kinase et de la 2-5A-synthetase au cours de l'infection virale, semblent etre en correlation avec la production d'interferon