384 research outputs found
The role of bone sialoprotein in the tendon-bone insertion
Tendons and ligaments insert into bone through a transitional tissue termed the enthesis which is susceptible to injury and difficult to repair. Entheses contain a region of calcified fibrocartilage (CFC), however mineral-associated proteins in this tissue remain poorly characterized. Bone sialoprotein (BSP) is a phosphoprotein associated with mineralizing tissues. In these studies BSP was identified in the CFC of entheses by immunohistochemistry. Analysis of the entheses of Bsp-/- mice indicate abnormalities in the CFC. Compared to controls, the CFC of the quadriceps tendon enthesis is 28% and 41 % longer in 15 week and 14 month old Bsp-/- mice, respectively. MicroCT and Raman spectroscopic analysis of the CFC in Bsp-/- mice demonstrate that mineral content is similar between genotypes. Mechanical studies show that the Bsp-/- patellar tendon is larger in cross-sectional area yet mechanically weaker. These data suggest BSP is involved in the regulation and growth of the CFC
Mechanistic understanding of dendritic cell activation in skin sensitization: additional evidences to support potency classification
Allergic contact dermatitis (ACD) is an important occupational and environmental disease caused by topical exposure to chemical allergens. In the EU, it has been calculated that 4 % of animals are used in toxicity test for the assessment of skin sensitization (Peiser et al., 2012). To come a complete replacement of animals, evaluation of relative skin sensitization potency is necessary. The identification of mechanisms influencing allergen potency requires a better understanding of molecular events that trigger cell activation. Therefore, (i) the effects of selected allergens on surface markers expression and cytokines release in contact allergen-induced cell activation were assessed, and (ii) the role of Protein Kinase C (PKC) beta activation in contact allergen-induced cell activation was investigated. The human pro-myelocytic cell line THP-1 was used as experimental model surrogate of dendritic cells. Cells were exposed to select contact allergens of different potency and cell surface marker expression (CD80, CD86, HLA-DR) was determined by flow cytometry analysis. Cytokines production (IL-6, IL-8, IL-10, IL-12p40, IL-18) was evaluated with specific sandwich ELISA. The effective contribution of PKC beta in chemical allergen-induced cell activation was assessed by Western Blot analysis (PKC beta activation) and using a specific PKC beta inhibitor (PKC beta pseudosubstrate). In addition, to investigate if contact allergens are able to induce indeed dendritic cells (DCs) maturation, THP-1 cells were differentiated to immature DC and then exposed to contact allergen of different potency. Overall, our finding provides insights into the process of sensitization and strength of cell activation associated with allergens of different potency. Results obtained suggest that contact allergens of different potency are able to induce a different degree of activation of dendritic cells maturation involved in the process of ACD
Review of the safety of octocrylene used as an ultraviolet filter in cosmetics
Octocrylene or octocrilene is an organic ultraviolet (UV) filter which absorbs mainly UVB radiation and short UVA wavelengths. It is used in various cosmetic products to either provide an appropriate sun protection factor in sunscreen products or to protect cosmetic formulations from UV radiation. There is no discussion that UV filters are beneficial ingredients in cosmetics since they protect from skin cancer, but octocrylene has been recently incriminated to potentially induce adverse effects on the endocrine system in addition to having allergic and/or photoallergic potential. However, the substance has the advantage to work synergistically with other filters allowing a beneficial broad photoprotection, e.g. it stabilizes the UVA filter avobenzone (i.e. butylmethoxydibenzoylmethane). Like all chemicals used in cosmetics, the safety profile of octocrylene is constantly under assessment by the European Chemical Agency (ECHA) since it has been registered according to the European regulation Registration, Evaluation, Authorisation and Restriction of Chemicals. Summaries of safety data of octocrylene are publicly available on the ECHA website. This review aims to present the main safety data from the ECHA website, as well as those reported in scientific articles from peer-reviewed journals. The available data show that octocrylene does not have any endocrine disruption potential. It is a rare sensitizer, photocontact allergy is more frequent and it is considered consecutive to photosensitization to ketoprofen. Based on these results, octocrylene can be considered as safe when used as a UV filter in cosmetic products at a concentration up to 10%
Toxicity of Biomass Combustion Generated Ultrafine Particles: Evidence from Stack-sampled and Airborne UFPs
Safety of titanium dioxide nanoparticles in cosmetics
Titanium dioxide (TiO2) is widely used in a variety of products including cosmetics. TiO2 in its nanoparticle form (nano-TiO2) is now the only form used as an ultraviolet (UV) filter in sunscreens, but also in some day creams, foundations and lip balms. While its efficacy as a UV filter is proven in the prevention of skin cancers and sunburns, some concerns have been raised about its safety. Indeed, considering its small size, nano-TiO2 is suspected to penetrate dermal, respiratory or gastrointestinal barriers, disseminate in the body and therefore constitute a potential risk to the consumer. At the skin level, most studies performed in humans or animals showed that nano-TiO2 did not penetrate beyond the outer layers of stratum corneum to viable cells and did not reach the general circulation, either in healthy or in compromised skin. The Scientific Committee on Consumer Safety (SCCS) considers nano-TiO2 as a non-sensitizer and as mild- or non-irritant to skin and concludes in no evidence of carcinogenicity (supported by the European Chemicals Agency), mutagenicity or reproductive toxicity after dermal exposure to nano-TiO2. According to the SCCS, nano-TiO2 from sunscreens does not present any health risk when applied on the skin at a concentration up to 25%. However, the SCCS does not recommend the use of nano-TiO2 in formulations that may lead to exposure of the consumer's lungs by inhalation (sprayable products and powders). Indeed, even if human data are sparse and inconsistent, lung inflammation was reported in animals. In 2016, the EU Cosmetic Regulation made nano-TiO2 as an authorized UV filter, except in products that could lead to exposure of the lungs. After oral exposure, nano-TiO2 absorption and toxicity are limited. The incidental oral exposure to nano-TiO2 contained in lip balms is thus not expected to induce adverse health effects
Safety review of phenoxyethanol when used as a preservative in cosmetics
Phenoxyethanol, or 2-phenoxyethanol, has a large spectrum of antimicrobial activity and has been widely used as a preservative in cosmetic products for decades. It is effective against various Gram-negative and Gram-positive bacteria, as well as against yeasts, and has only a weak inhibitory effect on resident skin flora. According to the European Scientific Committee on Consumer Safety, phenoxyethanol is safe for all consumers \u2013 including children of all ages \u2013 when used as a preservative in cosmetic products at a maximum concentration of 1%. Adverse systemic effects have been observed in toxicological studies on animals but only when the levels of exposure were many magnitudes higher (around 200-fold higher) than those to which consumers are exposed when using phenoxyethanol-containing cosmetic products. Despite its widespread use in cosmetic products, phenoxyethanol is a rare sensitizer. It can be considered as one of the most well-tolerated preservatives used in cosmetic products
Schiff Base Complexes of Copper(II)
The crystal structures of four Schiff base molecules are presented, one of which is a re-appraisal of a previously reported structure. Crystals of N,N\u27-1,2-phenylene-bis(salicylideneiminato)copper(II) have been grown from both chloroform and pyridine. The structure from chloroform shows two crystallographically distinct squareplanar molecules per asymmetric unit in an orthorhombic cell, a = 20.159(2), b = 14.918(1), c = 13.329(1) Ă…; space group Pna21. Two different stereochemistries are observed when pyridine is the solvent. One has square planar geometry and the other square pyramidal with a pyridine molecule bound in the fifth co-ordination site. The space group is P1 with a = 8.748(4), b = 14.499(4), c = 18.725(5) Ă…, α = 109.93(3), β = 91.99(2), γ = 101.64(3)°. Bis(N-phenyl pyridoxylideneiminato)copper(II) crystallises in a monoclinic cell, space group P21/c, a = 5.7037(6), b = 20.394(1), c = 10.6321(6) Ă…, β = 101.443(6)° with the trans square planar co-ordination geometry. In the re-appraised structure of aqua(5-phosphopyridoxylidene-DLphenylalanineato) copper(II) the complex is square pyramidal with two oxygen and one nitrogen donor from the ligand. The fourth site is occupied by a water molecule and the fifth, apical donor is a phosphate oxygen from an adjacent molecule. The space group is triclinic P1 with a = 8.697(2), b = 13.039(3), c = 12.418(3) Ă…, α = 110.49(2), β = 108.61(2), γ = 63.65(10)°
Effects of interpregnancy interval on pregnancy complications: protocol for systematic review and meta-analysis
Introduction: Interpregnancy interval (IPI) is the length of time between a birth and conception of the next pregnancy. Evidence suggests that both short and long IPIs are at increased risk of adverse pregnancy and perinatal outcomes. Relatively less attention has been directed towards investigating the effect of IPI on pregnancy complications, and the studies that have been conducted have shown mixed results. This systematic review will aim to provide an update to the most recent available evidence on the effect of IPI on pregnancy complications. Method and Analysis: We will search electronic databases such as Ovid/MEDLINE, EMBASE, CINAHL, Scopus, Web of Science and PubMed to identify peer-reviewed articles on the effects of IPI on pregnancy complications. We will include articles published from start of indexing until 12 February 2018 without any restriction to geographic setting. We will limit the search to literature published in English language and human subjects. Two independent reviewers will screen titles and abstracts and select full-text articles that meet the eligibility criteria. The Newcastle-Ottawa tool will be used to assess quality of observational studies. Where data permit, meta-analyses will be performed for individual pregnancy complications. A subgroup analyses by country categories (high-income vs low and middle-income countries) based on World Bank income group will be performed. Where meta-analysis is not possible, we will provide a description of data without further attempt to quantitatively pool results. Ethics and Dissemination: Formal ethical approval is not required as primary data will not be collected. The results will be published in peer-reviewed journals and presented at national and international conferences. Prospero Registration Number: CRD42018088578
Rhus coriaria l. Fruit extract prevents UV-A-induced genotoxicity and oxidative injury in human microvascular endothelial cells
Rhus coriaria L. (sumac) is a small plant widely diffused in the Mediterranean region. Its fruit are often consumed as a spice but are also present in traditional medicine of several countries. Recently, interest in this plant has increased and many scientific works reported its beneficial effects including antioxidant and anti-inflammatory properties. Plant extracts can be successfully used against ultraviolet rays, which are able to reach and damage the human skin; however, sumac extracts were never applied to this usage. Thus, in this study, we used a macerated ethanol extract of Rhus coriaria L. dried fruit (mERC) to demonstrate its preventive role against the damage induced by ultraviolet-A rays (UV-A) on microvascular endothelial cells (HMEC-1). In vitro effects of the extract pre-treatment and UV-A exposure were evaluated in detail. The antioxidant capacity was assessed by reactive oxygen species (ROS) formation and cellular antioxidant activity measurement. Genoprotective effects of mERC were investigated as well. Our findings indicate that the extract acts as a cell cycle inhibitor or apoptosis inducer, according to the level of damage. The present work provides new insights into the usage of Rhus coriaria extracts against skin injuries
Cyclosporin A exacerbates skin irritation induced by tributyltin by increasing nuclear factor \u3bab activation
In searching for pharmacologic agents able to reduce xenobiotic-induced skin irritation, we found that cyclosporine A exacerbates the skin irritation induced by tributyltin. We previously demonstrated the involvement of interleukin-1\u3b1 and tumor necrosis factor \u3b1 in tributyltin-induced skin irritation. Here, we show that cyclosporine A (28 mg per kg), at a dose that results in systemic immunosuppression, potentiates tributyltin-induced skin irritation through increased tumor necrosis factor \u3b1 production, associated with increased tributyltin-induced activation of transcription factor nuclear factor \u3baB in cyclosporine-A-treated mice. On the other hand, under the same experimental conditions, cyclosporine A prevented the elicitation phase of oxazolone-induced contact allergy, but was ineffective in preventing benzalkonium-chloride-induced skin irritation. Using a murine keratinocyte cell line (HEL30) we demonstrated, also in vitro, that the cyclosporine A potentiates tributyltin-induced nuclear factor \u3baB activation and cytokine production, this being preceded by an increase in cellular oxidative activity, essential for nuclear factor \u3baB activation, that is time and dose (0.1-10 \u3bcM) dependent. This effect was not exclusive to tributyltin but could be extended to other mitochondrial poisons such as sodium arsenate. It has been reported that cyclosporine A binds to cyclophilins. An 18-mer antisense phosphor-othioate oligodeoxynucleotide was used to target mitochondrial cyclophilin D mRNA. After 24 h exposure to the oligonucleotide, the amount of cyclophilin D in the cells was decreased by 54% as judged by Western blot analysis. Cyclophilin D suppression prevented cyclosporine A potentiation of tributyltin-induced cellular oxidative activity, indicating the key role of the binding of cyclosporine A to mitochondrial cyclophilin D in mediating this effect
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