Release of Metal Ions from Orthodontic Appliances: An In Vitro Study

In this paper, we report the results of an in vitro experiment on the release of metal ions from orthodontic appliances composed of alloys containing iron, chromium, nickel, silicon, and molybdenum into artificial saliva. The concentrations of magnesium, aluminum, silicon, phosphorus, sulfur, potassium, calcium, titanium, vanadium, manganese, iron, cobalt, copper, zinc, nickel, and chromium were significantly higher in artificial saliva in which metal brackets, bands, and wires used in orthodontics were incubated. In relation to the maximum acceptable concentrations of metal ions in drinking water and to recommended daily doses, two elements of concern were nickel (573 vs. 15 μg/l in the controls) and chromium (101 vs. 8 μg/l in the controls). Three ion release coefficients were defined: α, a dimensionless multiplication factor; β, the difference in concentrations (in micrograms per liter); and γ, the ion release coefficient (in percent). The elevated levels of metals in saliva are thought to occur by corrosion of the chemical elements in the alloys or welding materials. The concentrations of some groups of dissolved elements appear to be interrelated

PrzeciweozynofilowedziałanieIL-12 w hodowanej tkance ludzkiego polipa nosa

Rationale: Tissue eosinophilia is an important pathophysiological issue in bronchial ashma and nasal polyps. Its magnitude is regulated by several mechanisms, including selective migration of eossinophils to peripheral tissues and prolongation of survival. A key role in this processes is assigned to Th2 originating cytokines: IL-3, IL-5, GM-CSF. It has been previously demonstrated that IL-12 diminishes tissue eosinophilia in an animal model, and Hofstra showed that Il-12 together with IL-18 prevents allergen-induced increase bronchial hyperresponsiveness, BAL eosinophilia and the development of allergen-specific Th2 cells. Methods: Nasal polyps were obtained during routine surgery and were cultured in fragments of approximately 30 mg for 2, 6, and 15 days in RPMI 1640 in the absence or presence of IL-12. Afterwards a dose-dependency was tested at day 2 of culture. Polyp tissue from cultures was than processed to slides, stained with Giemsa and cells were counted in light microscopy (400x). Results: Eosinophils represented 62,8 &plusmn; 21,3% of residing cells in nasal polyps at the day 0. IL-12 (1 &#956;g/ml) caused a significant time-dependent decrease in the percentage of Eos after 2 and 6 days. The effect of IL-12 at day 2 was concentration-dependent: control, 28,2 &plusmn; 2,9; at 10 ng/ml, 13,9 &plusmn; 6,4 (n = 4, p < 0,05); at 100 ng/ml, 11,6 &plusmn; 2,1 (p < 0.01); at 1 &#956;g/ml, 7,5 &plusmn; 1,5 (p < 0,005). Conclusion: IL-12 acts as potent topical antieosinophilic agent. Its action can be seen in a cultured polyp environment. It is visible already after two days and is concentration-dependent. Further study is needed to elucidate tissue mechanisms of this action

Cytocompatibility of Medical Biomaterials Containing Nickel by Osteoblasts: a Systematic Literature Review

The present review is based on a survey of 21 studies on the cytocompatibility of medical biomaterials containing nickel, as assessed by cell culture of human and animal osteoblasts or osteoblast-like cells. Among the biomaterials evaluated were stainless steel, NiTi alloys, pure Ni, Ti, and other pure metals. The materials were either commercially available, prepared by the authors, or implanted by various techniques to generate a protective layer of oxides, nitrides, acetylides. The observation that the layers significantly reduced the initial release of metal ions and increased cytocompatibility was confirmed in cell culture experiments. Physical and chemical characterization of the materials was performed. This included, e.g., surface characterization (roughness, wettability, corrosion behavior, quantity of released ions, microhardness, and characterization of passivation layer). Cytocompatibility tests of the materials were conducted in the cultures of human or animal osteoblasts and osteoblast-like cells. The following assays were carried out: cell proliferation and viability test, adhesion test, morphology (by fluorescent microscopy or SEM). Also phenotypic and genotypic markers were investigated. In the majority of works, it was found that the most cytocompatible materials were stainless steel and NiTi alloy. Pure Ni was rendered and less cytocompatible. All the papers confirmed that the consequence of the formation of protective layers was in significant increase of cytocompatibility of the materials. This indicates the possible further modifications of the manufacturing process (formation of the passivation layer)

Building Slavery-free Communities: A Resilience Framework

There is growing interest in the use of community-based approaches to address the causes of modern slavery and the related goal of building anti-slavery 'resilience'. However, the concept of resilience is often poorly understood and applied without attention to the specific challenges of anti-slavery policy and practice. This paper provides a conceptual framework for understanding the process and outcomes of building resilience against contemporary forms of slavery within place-based communities. Inspired by established ecological models of resilience, we propose an adaptive 'resilience cycle' that activists and policymakers can draw upon to inform the process of designing and delivering policy interventions. This process is combined with a review of evidence about the multi-level social determinants of modern slavery to suggest a framework of topic areas for local review and measurement, as a means to assess existing gaps and assets, enable comparative learning and measure progress towards goals. We also outline a future research agenda exploring locally-grounded perspectives on modern slavery risk and resilience, to improve understanding of the factors underpinning resilience across different social and economic contexts. This article will assist policy-makers by clarifying the concept of anti-slavery resilience, which can in turn inform policy design and implementation, and help to make connections between disparate initiatives from multiple actors. By combining a process for building resilience with an overview of social determinants underpinning a slavery-free community, we offer a basis for gap-analysis and ongoing measurement. The research agenda that we outline to better understand factors underpinning resilience would make a valuable contribution to improving anti-slavery governance and assist in developing a better understanding of the linkages between achieving SDG 8.7 and wider sustainable development goals

Pets as Sentinels of Human Exposure to Neurotoxic Metals

The idea that animals may be used as sentinels of environmental hazards pending over humans and the associated public health implications is not a new one. Nowadays pets are being used as bioindicators for the effects of environmental contaminants in human populations. This is of paramount importance due to the large increase in the worldwide distribution of synthetic chemicals, particularly in the built environment. Companion animals share the habitat with humans being simultaneously exposed to and suffering the same disease spectrum as their masters. Moreover, their shorter latency periods (due to briefer lifespans) enable them to act as early warning systems, allowing timely public health interventions. The rise on ethical constraints on the use of animals and, consequently, on the sampling they can be subjected to has led to the preferential use of noninvasive matrices, and in this case we are looking into hair. This chapter focuses in three non-essential metals: mercury, lead, and cadmium, due to their ubiquitous presence in the built environment and their ability of affecting the mammal nervous system. There is a fairly short amount of studies reporting the concentrations of these metals in pets’ hair, particularly for cats. These studies are characterized, and the metal concentrations corresponding to different parameters (e.g., age, sex, diet, rearing) are described in order to provide the reader with a general vision on the use of this noninvasive matrix on the studies conducted since the last two decades of the twentieth century.publishe

The use of autogenous augmentation material obtained from the patient’s own teeth

Przeszczep tkanki kostnej jest powszechnie znaną i skuteczną metodą wypełniania ubytków osteolitycznych powstałych w wyniku urazów, działań chirurgicznych oraz stanów chorobowych (torbiele, zapalenie przyzębia). Jednym z kluczowych problemów związanych z tym zabiegiem jest ograniczenie ilości materiału możliwego do pobrania przez operatora od pacjenta. Ponadto zabieg na miejscu dawczym wiąże się z dodatkową raną kostną oraz może stanowić problem zarówno estetyczny, jak i funkcjonalny. Rozwiązaniem wymienionych problemów może być zastosowanie autogennych tkanek twardych zęba pacjenta. Zawierają one biozgodną macierz zębinową charakteryzującą się wysokiego rzędu podobieństwem histologicznym i biochemicznym do tkanki kostnej. Możliwość zastosowania materiału zębowego do wypełniania ubytków kostnych nie jest rozwiązaniem nowym – temat ten podejmowany był już w 1967 roku w badaniach nad właściwościami osteogennymi demineralizowanego materiału zębowego i rozwijany jest po dziś dzień. Obecnie do odbudowy tkanki kostnej wykorzystywany jest również materiał o pełnej zawartości frakcji mineralnej, którego użycie znacznie skraca czas zabiegu. W pracy przedstawiono właściwości autogennego materiału zębowego oraz sposób jego uzyskiwania.Bone tissue graft is a commonly recognised and efficient method of filling osteolitic cavities resulting from injuries, surgical procedures and lesions (cysts, periodontitis). One of the most crucial problems related to this procedure is the limitation of grafting material obtainable from the patient’s tissues. Moreover, graft donoring site operation is associated with an additional bone wound and might result in an aesthetical as well as functional problems. A solution for presented difficulties may be the use of autogenous tooth’s hard tissues, which contain biocompatible dentin matrix of a high histological and biochemical similarity to bone tissue. The possibility of using dental material for filling bone cavities is not a new solution – the osteogenic properties of demineralised dentin material were already examined in 1967 and this concept is still developing. Currently, a material with a full content of the mineral fraction is used for regeneration of bone tissues, which shortens the time of procedure significantly. The paper presents the properties of autologous dental material and a method of its obtaining