14 resultados para Cosmetic dentistry
em CentAUR: Central Archive University of Reading - UK
Resumo:
Many environmental compounds with oestrogenic activity are measurable in the human breast and oestrogen is a known factor in breast cancer development. Exposure to environmental oestrogens occurs through diet, household products and cosmetics, but concentrations of single compounds in breast tissue are generally lower than needed for assayable oestrogenic responses. Results presented here and elsewhere demonstrate that in combination, chemicals can give oestrogenic responses at lower concentrations, which suggests that in the breast, low doses of many compounds could sum to give a significant oestrogenic stimulus. Updated incidence figures show a continued disproportionate incidence of breast cancer in Britain in the upper outer quadrant of the breast which is also the region to which multiple cosmetic chemicals are applied. CONCLUSION: If exposure to complex mixtures of oestrogenic chemicals in consumer products is a factor in breast cancer development, then a strategy for breast cancer prevention could become possible.
Resumo:
Benzyl salicylate, benzyl benzoate and butylphenylmethylpropional (Lilial) are added to bodycare cosmetics used around the human breast. We report here that all three compounds possess oestrogenic activity in assays using the oestrogen-responsive MCF7 human breast cancer cell line. At 3 000 000-fold molar excess, they were able to partially displace [H-3]oestradiol from recombinant human oestrogen receptors ER alpha and ER beta, and from cytosolic ER of MCF7 cells. At concentrations in the range of 5 x 10(-5) to 5 x 10(-4) M, they were able to increase the expression of a stably integrated oestrogen-responsive reporter gene (ERE-CAT) and of the endogenous oestrogen-responsive pS2 gene in MCF7 cells, albeit to a lesser extent than with 10(-8) M 17 beta-oestradiol. They increased the proliferation of oestrogen-dependent MCF7 cells over 7 days, which could be inhibited by the antioestrogen fulvestrant, suggesting an ER-mediated mechanism. Although the extent of stimulation of proliferation over 7 days was lower with these compounds than with 10(-8) M 17 beta-oestradiol, given a longer time period of 35 days the extent of proliferation with 10(-4) M benzyl salicylate, benzyl benzoate or butylphenylmethylpropional increased to the same magnitude as observed with 10(-8) M 17 beta-oestradiol over 14 days. This demonstrates that benzyl salicylate, benzyl benzoate and butylphenylmethylpropional are further chemical components of cosmetic products which give oestrogenic responses in a human breast cancer cell line in culture. Further research is now needed to investigate whether oestrogenic responses are detectable using in vivo models and the extent to which these compounds might be absorbed through human skin and might enter human breast tissues. Copyright (C) 2009 John Wiley & Sons, Ltd.
Resumo:
The established role of oestrogen in the development and progression of breast cancer raises questions concerning a potential contribution from the many chemicals in the environment which can enter the human breast and which have oestrogenic activity. A range of organochlorine pesticides and polychlorinated bipheryls possess oestrogen-mimicking properties and have been measured in human breast adipose tissue and in human milk. These enter the breast from varied environmental contamination of food, water and air, and due to their lipophilic properties can accumulate in breast fat. However, it is emerging that the breast is also exposed to a range of oestrogenic chemicals applied as cosmetics to the underarm and breast area. These cosmetics are left on the skin in the appropriate area, allowing a more direct dermal absorption route for breast exposure to oestrogenic chemicals and allowing absorbed chemicals to escape systemic metabolism. This review considers evidence in support of a functional role for the combined interactions of cosmetic chemicals with environmental oestrogens, pharmacological oestrogens, phyto-oestrogens and physiological oestrogens in the rising incidence of breast cancer.
Resumo:
Aluminium salts are used as the active antiperspirant agent in underarm cosmetics, but the effects of widespread, long term and increasing use remain unknown, especially in relation to the breast, which is a local area of application. Clinical studies showing a disproportionately high incidence of breast cancer in the upper outer quadrant of the breast together with reports of genomic instability in outer quadrants of the breast provide supporting evidence for a role for locally applied cosmetic chemicals in the development of breast cancer. Aluminium is known to have a genotoxic profile, capable of causing both DNA alterations and epigenetic effects, and this would be consistent with a potential role in breast cancer if such effects occurred in breast cells. Oestrogen is a well established influence in breast cancer and its action, dependent on intracellular receptors which function as ligand-activated zinc finger transcription factors, suggests one possible point of interference from aluminium. Results reported here demonstrate that aluminium in the form of aluminium chloride or aluminium chlorhydrate can interfere with the function of oestrogen receptors of MCF7 human breast cancer cells both in terms of ligand binding and in terms of oestrogen-regulated reporter gene expression. This adds aluminium to the increasing list of metals capable of interfering with oestrogen action and termed metal I oestrogens. Further studies are now needed to identify the molecular basis of this action, the longer term effects of aluminium exposure and whether aluminium can cause aberrations to other signalling pathways in breast cells. Given the wide exposure of the human population to antiperspirants, it will be important to establish dermal absorption in the local area of the breast and whether long term low level absorption could play a role in the increasing incidence of breast cancer. (c) 2005 Elsevier Inc. All rights reserved.
Resumo:
Parabens are used as preservatives in many thousands of cosmetic, food and pharmaceutical products to which the human population is exposed. Although recent reports of the oestrogenic properties of parabens have challenged current concepts of their toxicity in these consumer products, the question remains as to whether any of the parabens can accumulate intact in the body from the long-term, low-dose levels to which humans are exposed. Initial studies reported here show that parabens can be extracted from human breast tissue and detected by thin-layer chromatography. More detailed studies enabled identification and measurement of mean concentrations of individual parabens in samples of 20 human breast tumours by high-pressure liquid chromatography followed by tandem mass spectrometry. The mean concentration of parabens in these 20 human breast tumours was found to be 20.6 +/- 4.2 ng g(-1) tissue. Comparison of individual parabens showed that methylparaben was present at the highest level (with a mean value of 12.8 +/- 2.2 ng g(-1) tissue) and represents 62% of the total paraben recovered in the extractions. These studies demonstrate that parabens can be found intact in the human breast and this should open the way technically for more detailed information to be obtained on body burdens of parabens and in particular whether body burdens are different in cancer from those in normal tissues. Copyright (C) 2004 John Wiley Sons, Ltd.
Resumo:
In the decade that has elapsed since the suggestion that exposure of the foetal/developing male to environmental oestrogens could be the cause of subsequent reproductive and developmental effects in men, there has been little definitive research to provide conclusions to the hypothesis. Issues of exposure and low potency of environmental oestrogens may have reduced concerns. However, the hypothesis that chemicals applied in body care cosmetics (including moisturizers, creams, sprays or lotions applied to axilla or chest or breast areas) may be affecting breast cancer incidence in women presents a different case scenario, not least in the consideration of the exposure issues. The specific cosmetic type is not relevant but the chemical ingredients in the formulations and the application to the skin is important. The most common group of body care cosmetic formulation excipients, namely p-hydroxybenzoic acid esters or parabens, have been shown recently to be oestrogenic in vitro and in vivo and now have been detected in human breast tumour tissue, indicating absorption (route and causal associations have yet to be confirmed). The hypothesis for a link between oestrogenic ingredients in underarm and body care cosmetics and breast cancer is forwarded and reviewed here in terms of. data on exposure to body care cosmetics and parabens, including dermal absorption; paraben oestrogenicity; the role of oestrogen in breast cancer; detection of parabens in breast tumours; recent epidemiology studies of underarm cosmetics use and breast cancer; the toxicology database; the current regulatory status of parabens and regulatory toxicology data uncertainties. Notwithstanding the major public health issue of the causes of the rising incidence of breast cancer in women, this call for further research may provide the first evidence that environmental factors may be adversely affecting human health by endocrine disruption, because exposure to oestrogenic chemicals through application of body care products (unlike diffuse environmental chemical exposures) should be amenable to evaluation, quantification and control. The exposure issues are clear and the exposed population is large, and these factors should provide the necessary impetus to investigate this potential issue of public health. Copyright (C) 2004 John Wiley Sons, Ltd.
Resumo:
The antioxidant and tyrosinase inhibitory properties of extracts of mango seed kernel (Mangifera indica L.), which is normally discarded when the fruit is processed, were studied. Extracts contained phenolic components by a high antioxidant activity, which was assessed in homogeneous solution by the 2,2-diphenyt-1-picrylhydrazyl radical and 2,2'-azinobis (3-ethylbenzothialozinesulfonic acid) radical cation-scavenging assays and in an emulsion with the ferric thiocyanate test. The extracts also possessed tyrosinase inhibitory activity. Drying conditions and extraction solvent were varied, and optimum conditions for preparation of mango seed kernel extract were found to be sun-drying with ethanol extraction at room temperature. Refluxing in acidified ethanol gave an increase in yield and the obtained extract had the highest content of total phenolics, and also was the most effective antioxidant with the highest radical-scavenging, metal-chelating and tyrosinase inhibitory activity. The extracts did not cause acute irritation of rabbit skins. Our study for the first time reveals the high total phenol content, radical-scavenging, metal-chelating and tyrosinase inhibitory activities of the extract from mango seed kernel. This extract may be suitable for use in food, cosmetic, nutraceutical and pharmaceutical applications. (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
Studying peptide amphiphiles (PAs), we investigate the influence of alkyl chain length on the aggregation behavior of the collagen-derived peptide KTTKS with applications ranging from antiwrinkle cosmetic creams to potential uses in regenerative medicine. We have studied synthetic peptides amphiphiles C14− KTTKS (myristoyl Lys-Thr-Thr-Lys-Ser) and C18−KTTKS(stearoyl-Lys-Thr Thr-Lys-Ser) to investigate in detail their physicochemical properties. It is presumed that the hydrophobic chain in these self-assembling peptide amphiphiles enhances peptide permeation across the skin compared to KTTKS alone. Subsequently Cn−KTTKS should act as a prodrug and release the peptide by enzymatic cleavage. Our results should be useful in the further development of molecules with collagen-stimulating activity.
Resumo:
This paper explores the nature of private social and environmental reporting (SER). From interviews with UK institutional investors, we show that both investors and investees employ Goffmanesque, staged impression management as a means of creating and disseminating a dual myth of social and environmental accountability. The interviewees’ utterances unveil private meetings imbued with theatrical verbal and physical impression management. Most of the time, the investors’ shared awareness of reality belongs to a Goffmanesque frame whereby they accept no intentionality, misrepresentation or fabrication, believing instead that the ‘performers’ (investees) are not intending to deceive them. A shared perception that social and environmental considerations are subordinated to financial issues renders private SER an empty encounter characterised as a relationship-building exercise with seldom any impact on investment decision-making. Investors spoke of occasional instances of fabrication but these were insufficient to break the frame of dual myth creation. They only identified a handful of instances where intentional misrepresentation had been significant enough to alter their reality and behaviour. Only in the most extreme cases of fabrication and lying did the staged meeting break frame and become a genuine occasion of accountability, where investors demanded greater transparency, further meetings and at the extreme, divested shares. We conclude that the frontstage, ritualistic impression management in private SER is inconsistent with backstage activities within financial institutions where private financial reporting is prioritised. The investors appeared to be in a double bind whereby they devoted resources to private SER but were simultaneously aware that these efforts may be at best subordinated, at worst ignored, rendering private SER a predominantly cosmetic, theatrical and empty exercise.
Resumo:
This paper explores the nature of private social and environmental reporting (SER). From interviews with UK institutional investors, we show that both investors and investees employ Goffmanesque, staged impression management as a means of creating and disseminating a dual myth of social and environmental accountability. The interviewees’ utterances unveil private meetings imbued with theatrical verbal and physical impression management. Most of the time, the investors’ shared awareness of reality belongs to a Goffmanesque frame whereby they accept no intentionality, misrepresentation or fabrication, believing instead that the ‘performers’ (investees) are not intending to deceive them. A shared perception that social and environmental considerations are subordinated to financial issues renders private SER an empty encounter characterised as a relationship-building exercise with seldom any impact on investment decision-making. Investors spoke of occasional instances of fabrication but these were insufficient to break the frame of dual myth creation. They only identified a handful of instances where intentional misrepresentation had been significant enough to alter their reality and behaviour. Only in the most extreme cases of fabrication and lying did the staged meeting break frame and become a genuine occasion of accountability, where investors demanded greater transparency, further meetings and at the extreme, divested shares. We conclude that the frontstage, ritualistic impression management in private SER is inconsistent with backstage activities within financial institutions where private financial reporting is prioritised. The investors appeared to be in a double bind whereby they devoted resources to private SER but were simultaneously aware that these efforts may be at best subordinated, at worst ignored, rendering private SER a predominantly cosmetic, theatrical and empty exercise.
Resumo:
Regeneration of periodontal tissues aims to utilize tissue engineering techniques to restore lost periodontal tissues including the cementum, periodontal ligament and alveolar bone. Regenerative dentistry and its special field regenerative periodontology represent relatively new and emerging branches of translational stem cell biology and regenerative medicine focusing on replacing and regenerating dental tissues to restore or re-establish their normal function lost during degenerative diseases or acute lesions. The regeneration itself can be achieved through transplantation of autologous or allogenic stem cells, or by improving the tissue self-repair mechanisms (e.g. by application of growth factors). In addition, a combination of stem cells or stem cell-containing tissue with bone implants can be used to improve tissue integration and the clinical outcome. As the oral cavity represents a complex system consisting of teeth, bone, soft tissues and sensory nerves, regenerative periodontology relies on the use of stem cells with relatively high developmental potential. Notably, the potential use of pluripotent stem cell types such as human embryonic stem cells or induced pluripotent stem cells is still aggravated by ethical and practical problems. Thus, other cellular sources such as those readily available in the postnatal craniofacial area and particularly in oral structures offer a much better and realistic alternative as cellular regenerative sources. In this review, we summarize current knowledge on the oral neural crest-derived stem cell populations (oNCSCs) and discuss their potential in regenerative periodontology.
Resumo:
Paddy Hartley's work is primarily concerned with the ways in which the human face can be repaired, manipulated and recontextualised, and the questions these processes raise about our concepts of beauty and disfigurement. Incorporating surgical and pharmaceutical equipment as well as steel, scrap metal, digital embroidery and textiles, Hartley sets out a critique of how we think about the face today. Taking as a starting point records of facially injured servicemen of the First World War and the pioneering surgery they underwent, Project Facade examines the impact of disfigurement on the human psyche, as well as tracing the development of early facial reconstructive surgery. His Face Corsets, meanwhile, examines attitudes towards cosmetic surgery and the beauty industry, providing a non-surgical means to brutally mimic the results of cosmetic procedures and beyond. The series gained notoriety and success in a wide variety of popular publications both nationally and internationally, and continue to feature in contemporary textiles and fashion publications. Paddy Hartley: Of Faces and Facades brings together these works in book form for the first time, presenting previously unpublished texts from David Houston Jones and Marjorie Gehrhardt, as well as drawings and photographs which document a remarkable creative process and a history that is still insufficiently explored.
Resumo:
Background Childhood dental anxiety is very common, with 10–20 % of children and young people reporting high levels of dental anxiety. It is distressing and has a negative impact on the quality of life of young people and their parents as well as being associated with poor oral health. Affected individuals may develop a lifelong reliance on general anaesthetic or sedation for necessary dental treatment thus requiring the support of specialist dental services. Children and young people with dental anxiety therefore require additional clinical time and can be costly to treat in the long term. The reduction of dental anxiety through the use of effective psychological techniques is, therefore, of high importance. However, there is a lack of high-quality research investigating the impact of cognitive behavioural therapy (CBT) approaches when applied to young people’s dental anxiety. Methods/design The first part of the study will develop a profile of dentally anxious young people using a prospective questionnaire sent to a consecutive sample of 100 young people referred to the Paediatric Dentistry Department, Charles Clifford Dental Hospital, in Sheffield. The second part will involve interviewing a purposive sample of 15–20 dental team members on their perceptions of a CBT self-help resource for dental anxiety, their opinions on whether they might use such a resource with patients, and their willingness to recruit participants to a future randomised controlled trial (RCT) to evaluate the resource. The third part of the study will investigate the most appropriate outcome measures to include in a trial, the acceptability of the resource, and retention and completion rates of treatment with a sample of 60 dentally anxious young people using the CBT resource. Discussion This study will provide information on the profile of dentally anxious young people who could potentially be helped by a guided self-help CBT resource. It will gain the perceptions of dental care team members of guided self-help CBT for dental anxiety in young people and their willingness to recruit participants to a trial. Acceptability of the resource to participants and retention and completion rates will also be investigated to inform a future RCT.