14 research outputs found

    Immunotoxicity and Sensitizing Capacity of Metal Compounds Depend on Speciation

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    Immunotoxicity of metal compounds is an issue of great importance due to the recent industrial application of metals with unknown toxicity on the immune system and the discovery of metal intermediary compounds not sufficiently studied yet. In this report we show results of our study on the immunotoxicity of the following metals: the Platinum group elements (Platinum, Palladium, Rhodium), Titanium and Arsenic. We applied functional and non functional assays and investigated both innate and adaptive immune systems, in particular, cell proliferation, cytokine production by PBMCs and O−2 production by neutrophils. We obtained the following results: only some Ti compounds (Titanocene, Ti ascorbate and Ti oxalate) show immunotoxicity. Trivalent As compounds (Sodium arsenite and tetraphenyl arsonium chloride) are more immunotoxic than the other investigated As compounds. Genotoxicity of Pt group compounds is in the following order: Pt < Rh < Pd. Immunotoxicity of Pt group compounds is in the following order: Pd < Pt < Rh. Lymphocytes and macrophages show a different reaction of neutrophils to metal toxicity. We can conclude that these studies show that metal immunotoxicity depends on speciation. In general speciation provides additional and often essential information in evaluating metal toxicity. However, there are many difficulties in applying speciation in investigating toxico-kinetic aspects to many metals, mainly due to the lack of information about the existence and significance of species and to the lack of analytical methods for measuring species in biological samples

    Oral hyposensitization to nickel induces clinical improvement and a decrease in TH1 and TH2 cytokines in patients with systemic nickel allergy syndrome.

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    Some patients with nickel (Ni) allergic contact dermatitis suffer from systemic (intestinal or cutaneous) symptoms after ingestion of Ni-rich foods and experience symptoms reduction with low-Ni diet, a condition termed "systemic Ni allergy syndrome" (SNAS). We aimed at evaluating whether oral administration of low nickel doses improved clinical conditions and modulated immunological aspects of SNAS, without significant side effects. Thirty-six SNAS patients were enrolled. Treatment started after 1-month of low-Ni diet and consisted in an incremental oral NiOH dose phase (0.3ng to 1.5 μg/week) followed by a 12-months maintenance phase (1.5 μg/week). Randomly, twenty-four patients added Ni therapy to low-Ni diet and 12 remained with diet alone. All patients were allowed rescue medications (antihistamines and topical steroids). After 4 months, Ni-rich foods were gradually reintroduced. In vitro allergen-driven IL13, IL5 and IFNγ release by peripheral blood mononuclear cells was evaluated before and after treatment. Twenty-three patients receiving NiOH and the 12 control patients completed the study. Evaluation of SNAS clinical severity (by VAS and drug consumption) showed a significant difference in favor of NiOH-treated patients compared to controls. Twenty of 23 patients in the NiOH group and none in the control group tolerated Ni-rich food reintroduction. Release of all studied cytokines in culture supernatants was significantly lower after NiOH treatment. In conclusion NiOH is effective in reducing symptoms and drug consumption in SNAS and is able to modulate inflammatory parameters

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Proximity effects on nuclear spin-spin coupling constants. 1. 1J(CH) couplings in the vicinity of an atom bearing lone pairs

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    Proximity effects on 1J(CH) couplings are studied from a theoretical point of view in the following systems: CH4/FH (A) and H2O/HCN (B) which form dimers by hydrogen-bond interactions. 1J(CH) couplings for different intermolecular distances are calculated for the C - H bond facing the atom bearing lone pairs. While in the former system, this coupling is increased owing to the proximity to the F atom; in the latter this coupling is decreased owing to the proximity to the O atom. These opposite trends are accompanied by slight shortening and lengthening, respectively, of the corresponding C - H bond lengths. As part of this work, measurements of 1J(CH) couplings in 9-(1,3-dioxolan-2-yl)-1,2,3,4-tetrafluorotriptycene (I) and 1-formyl-2-hydroxy-8-fluoronaphthalene (II) and 1J(NH) in o-fluorobenzamide (III), showing proximity effects as those described above are carried out. These results suggest that 1J(XH) couplings are adequate probes to distinguish two different types of X-H⋯Y hydrogen bonds. © 1994 American Chemical Society.Fil:Vizioli, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:De Ruiz Azúa, M.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Giribet, C.G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Contreras, R.H. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Oral Hyposensitization to Nickel Induces Clinical Improvement and a Decrease in TH1 and TH2 Cytokines in Patients with Systemic Nickel Allergy Syndrome

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    Some patients with nickel (Ni) allergic contact dermatitis suffer from systemic (intestinal or cutaneous) symptoms after ingestion of Ni-rich foods and experience symptoms reduction with low-Ni diet, a condition termed "systemic Ni allergy syndrome" (SNAS). We aimed at evaluating whether oral administration of low nickel doses improved clinical conditions and modulated immunological aspects of SNAS, without significant side effects. Thirty-six SNAS patients were enrolled. Treatment started after 1-month of low-Ni diet and consisted in an incremental oral NiOH dose phase (0.3ng to 1.5 μg/week) followed by a 12-months maintenance phase (1.5 μg/week). Randomly, twenty-four patients added Ni therapy to low-Ni diet and 12 remained with diet alone. All patients were allowed rescue medications (antihistamines and topical steroids). After 4 months, Ni-rich foods were gradually reintroduced. In vitro allergen-driven IL13, IL5 and IFNγ release by peripheral blood mononuclear cells was evaluated before and after treatment. Twenty-three patients receiving NiOH and the 12 control patients completed the study. Evaluation of SNAS clinical severity (by VAS and drug consumption) showed a significant difference in favor of NiOH-treated patients compared to controls. Twenty of 23 patients in the NiOH group and none in the control group tolerated Ni-rich food reintroduction. Release of all studied cytokines in culture supernatants was significantly lower after NiOH treatment. In conclusion NiOH is effective in reducing symptoms and drug consumption in SNAS and is able to modulate inflammatory parameters

    Films of poly (L - lactic acid) / poly(hydroxybutyrate-co-hydroxyvalerate) blends: in vitro degradation

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    Biocompatible and biodegradable polymers have been studied in the last few years with good clinical success in the fixation and stabilization of bone fractures. The understanding and the control of the polymeric prosthetic degradation process and the effect of its degradation products in the organism are crucial for the success of the implant. In this present work, blends of PLLA/PHBV, obtained in several compositions by casting of solvent, obtaining samples in the form of films. The samples were characterized by the analysis of TGA, DSC, DMA and SEM. The results obtained showed that the PLLA/PHBV blends are immiscible, and present a discrete separation by microscopy. The blends obtained showed porous fracture surfaces. It is noticed that PLLA begins its degradation in a few weeks (around 2 weeks), unlike PHBV, where it was possible to observe eventual degradation up to 53 weeks. It was also observed that the blend increased its crystallinity with degradation
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