Suicide par sulfure d'hydrogène et délai post mortem long : à propos d'un cas. [Suicide by hydrogen sulfide inhalation and significant post mortem delay: A case report].

L'hydrogène sulfuré (H2S) est un gaz toxique retrouvé à l'état naturel et dans certains milieux industriels, à l'origine d'intoxication accidentelle, mais pouvant être également et facilement synthétisé de manière domestique. Des cas de suicide par hydrogène sulfuré ont ainsi été décrits à partir de produits ménagers dans la littérature depuis 2009, aux États-Unis et au Japon. La plupart présentait des délais post mortem (DPM) courts (moins de 72 heures). En France, les intoxications aiguës à l'H2S demeurent rares et sont le plus souvent liées à des accidents du travail. Nous rapportons ici le cas d'un homme âgé de 37 ans découvert à son domicile, en état de décomposition avancée avec un DPM de deux mois. Compte tenu de la présence d'une importante signalétique avisant du danger potentiel d'exposition à l'H2S, des mesures de précaution ont été mises en oeuvre dès la découverte du corps et poursuivies jusqu'aux opérations d'autopsie. Les analyses toxicologiques ont confirmé la présence d'H2S au niveau des prélèvements de cerveau et de muscle. Le cas présenté constitue le premier cas de suicide avec un délai post mortem long à l'H2S rapporté en France. Dans la littérature, les constatations macroscopiques à l'autopsie ne sont pas spécifiques tandis que les analyses toxicologiques reposent essentiellement sur la recherche et la quantification d'H2S. En raison de leur redistribution post mortem, les résultats de ces analyses doivent être interprétés avec prudence, et encore plus en cas de délai post mortem long et de phénomènes de putréfaction qui peuvent également être une source de génération d'H2S post mortem. Hydrogen sulfide (H2S) which is a poisonous gas found either in the natural state or in industrial environments and potentially linked with accidental intoxication, can also be easily handmade. Several cases of suicide by inhaling H2S produced by mixing household products have been reported in the literature since 2009 in USA and Japan. Most of them involved short post mortem delays up to 72 hours. In France, acute H2S poisoning remains rare and mostly accidental. We report the case of a 37-year-old man found at home, in an advanced stage of decomposition with a 2-month post mortem delay. As numerous warning signs about a high risk of H2S exposure were present, some precautionary measures were taken from the discovery of the cadaver to the autopsy. Toxicological analyses confirmed the presence of H2S in brain and muscle samples. This observation is the first French case with a long post mortem delay. As macroscopic findings in such cases are described to be unspecific in literature, toxicological analysis must focus on the detection and the quantification of H2S. However, due to the phenomena of post mortem drug redistribution and neo-formation, their results should be interpreted with much more caution when the post mortem delay is long. The potential increase in such voluntary-intoxication-related-deaths in France, similar to the recent Japanese and American waves of suicides, requires for forensic scientists, a good knowledge of both thanatological and toxicological pictures, and precautionary measures to adopt in such situations.

Kaivosteollisuudessa syntyvän kipsin hyödyntäminen

Diplomityön tarkoituksena oli tutkia ja kehittää käyttökohde kaivosteollisuudessa syntyvälle märälle kipsisivuvirralle, joka sisältää metalliepäpuhtauksina alumiinia, rautaa ja mangaania ja jonka määrä on noin 1 000 000 t/a. Kirjallisuuden pohjalta tutkittiin aluksi mahdollisuutta hyödyntää kipsiaines asfaltti- ja sementtiteollisuuden raaka-aineena. Sementin joukkoon lisätään tavallisesti noin 5 p-% kipsiä, mutta harvinaisimpiin sementtilaatuihin sitä voidaan lisätä jopa 30 p-%. Tästä huolimatta vain pieni osa tutkimuksen kohteessa syntyvästä kipsisivuvirrasta voitaisiin hyödyntää tässä sovelluksessa. Lisäksi kipsisivuvirran sisältämät epäpuhtaudet täytyisi poistaa tai saattaa inaktiiviseen muotoon. Myöskään sen kosteuspitoisuus ei saisi olla suuri. Näin ollen tämän kipsisivuvirran hyödyntäminen asfaltti- ja sementtiteollisuuden lisäaineena ei ole mahdollista Seuraavaksi harkittiin kipsin kierrättämistä, jolloin yhtenä vaihtoehtona oli hajottaa kipsi termisesti rikkioksideiksi ja valmistaa niistä rikkihappoa. Taloudellisista syistä hajoamistuotteen on oltava rikkitrioksidia, josta voitaisiin veteen imeyttämällä valmistaa rikkihappoa. Kipsin hajottaminen termovaa´alla osoitti, että kipsi vaatii noin 1400 ºC:n lämpötilan ja haihtuvat komponentit ovat H2O, SO ja SO2, muttei SO3. Alempien oksidien muuttaminen rikkihapoksi vaatisi katalyyttisen hapetuksen, mikä olisi käytännössä liian kallista. Toisena vaihtoehtona kipsin kierrättämiseksi tutkittiin sen biologista pelkistämistä rikkivedyksi ja kalsiumhydroksidilietteeksi. Laboratoriossa Ca(OH)2-lietteestä valmistettiin hiilidioksidin avulla kalsiumkarbonaattia, jolloin päästiin 90 %:n kalsiumhydroksidin konversiossa. Lisäksi alumiinihydroksidi saatiin erotettua kipsilietteestä kokeellisesti hydrosyklonin avulla. Diplomityössä päädyttiin siihen, että sulfaatin biologinen pelkistäminen ja alumiinihydroksidin mekaaninen erotus jatkuvatoimisesti on varteenotettava vaihtoehto kipsisivuvirran hyödyntämiseksi.

Iron metabolism and incidence of metabolic syndrome.

BACKGROUND AND AIMS: Whether iron metabolism affects metabolic syndrome (METS) is debated. We assessed the association between several markers of iron metabolism and incidence of METS. METHODS AND RESULTS: Data from 3271 participants (1870 women, 51.3 ± 10.4 years), free of METS at baseline and followed for 5.5 years. The association of serum iron, ferritin and transferrin with incident METS was assessed separately by gender. Incidence of METS was 22.6% in men and 16.5% in women (p < 0.001). After multivariate adjustment, a positive association was found between transferrin and incident METS in men: odds ratio (OR) and 95% confidence interval for the fourth relative to the first quartile 1.55 (1.04-2.31), p for trend = 0.03, while no association was found for iron OR = 0.81 (0.53-1.24), p for trend = 0.33 and ferritin OR = 1.30 (0.88-1.92), p for trend = 0.018. In women, a negative association was found between iron and incident METS: OR for the fourth relative to the first quartile 0.51 (0.33-0.80), p for trend<0.03; the association between transferrin and incident METS was borderline significant: OR = 1.45 (0.97-2.17), p for trend = 0.07 and no association was found for ferritin: OR = 1.11 (0.76-1.63), p for trend = 0.58. CONCLUSION: Transferrin, not ferritin, is independently associated with an increased risk of incident METS; the protective effect of iron in women should be further explored.

Plant uses in different bronze and iron age settlements from the Nuoro province (Sardinia). The results of phytolith analyses from several ceramic fragments and grinding stones.

Ceramic vessels and milling stones are important components of the archaeological record in several Nuraghi from the Pranemuru Plateau (Sardinia). To obtain information on the possible uses of the milling stones and the content vessels is of great interest to understand the economical activities carried out in these sites by these populations. One of the approaches to obtain information on the plant uses was the phytolith analyses of the sediment adhered both to the surface of the milling stones and to the surface of the vessel content. In total we analyzed eleven archaeological samples and two control samples collected from five different Nuraghi in the Pranemuru Plateau (Nuoro Province, Sardinia). The Nuraghi were located in an area of 10 km radius from nuraghe Arrubiu and were chronologically ascribed to the Bronze Age and one site -Pranu Illixi- to the Iron Age.

Targeting iron-mediated retinal degeneration by local delivery of transferrin.

Iron is essential for retinal function but contributes to oxidative stress-mediated degeneration. Iron retinal homeostasis is highly regulated and transferrin (Tf), a potent iron chelator, is endogenously secreted by retinal cells. In this study, therapeutic potential of a local Tf delivery was evaluated in animal models of retinal degeneration. After intravitreal injection, Tf spread rapidly within the retina and accumulated in photoreceptors and retinal pigment epithelium, before reaching the blood circulation. Tf injected in the vitreous prior and, to a lesser extent, after light-induced retinal degeneration, efficiently protected the retina histology and function. We found an association between Tf treatment and the modulation of iron homeostasis resulting in a decrease of iron content and oxidative stress marker. The immunomodulation function of Tf could be seen through a reduction in macrophage/microglial activation as well as modulated inflammation responses. In a mouse model of hemochromatosis, Tf had the capacity to clear abnormal iron accumulation from retinas. And in the slow P23H rat model of retinal degeneration, a sustained release of Tf in the vitreous via non-viral gene therapy efficently slowed-down the photoreceptors death and preserved their function. These results clearly demonstrate the synergistic neuroprotective roles of Tf against retinal degeneration and allow identify Tf as an innovative and not toxic therapy for retinal diseases associated with oxidative stress.

Influence of process parameters on part quality and mechanical properties for DMLS and SLM with iron-based materials

Rapid manufacturing is an advanced manufacturing technology based on layer-by-layer manufacturing to produce a part. This paper presents experimental work carried out to investigate the effects of scan speed, layer thickness, and building direction on the following part features: dimensional error, surface roughness, and mechanical properties for DMLS with DS H20 powder and SLM with CL 20 powder (1.4404/AISI 316L). Findings were evaluated using ANOVA analysis. According to the experimental results, build direction has a significant effect on part quality, in terms of dimensional error and surface roughness. For the SLM process, the build direction has no influence on mechanical properties. Results of this research support industry estimating part quality and mechanical properties before the production of parts with additive manufacturing, using iron-based powders

Markers of iron metabolism and metabolic syndrome in Swiss adults

Plusieurs études populationnelles ont montré l'existence d'une association entre des taux sanguins élevés de transferrine et le syndrome métabolique (SM). Bien que cette association soit bien établie, restent encore à être décrites les associations entre le SM et les autres marqueurs sanguins du métabolisme du fer, tels que le fer, la transferrine (Tsf), la capacité totale de fixation de la transferrine (CTF) ou la saturation de la transferrine (SaTsf) sanguins. Le but de notre étude a été d'identifier les associations entre les différents marqueurs du métabolisme du fer (fer, ferritine, Tsf, CTF et SaTsf) et le SM. Les données de l'étude CoLaus, récoltées entre 2003 et 2006, ont été utilisées. Le SM était défini selon les critères du National Cholesterol Education Program Adult Panel III. L'analyse statistique a été faite en stratifiant selon le genre ainsi que le status ménopausal chez les femmes. Des 6733 participants, 1235 (18%) ont été exclus de fait d'absence de données concernant les variables qui nous intéressaient, ou chez qui nous avons soupçonné une possible hémochromatose non diagnostiquée (SaTsf> 50%). Des 5498 participants restant (âge moyen ± écart-type: 53 ± 11 ans), 2596 étaient des hommes, 1285 des femmes pré- et 1617 des femmes postménopausées. La prévalence du SM était de 29,4% chez les hommes, 8,3% et 25,5% chez les femmes pré- et postménopausées, respectivement. Dans les trois groupes, la prévalence du SM était la plus haute dans les quartiles les plus élevés de ferritine, Tsf et CTF, ainsi que dans le quartile le plus bas de SaTsf. Après ajustement sur l'âge, l'indice de masse corporelle, la protéine C réactive, la consommation de tabac et/ou d'alcool, la prise de suppléments en fer et les marqueurs hépatiques, l'appartenance au quartile le plus élevé de ferritine, Tsf ou CTF était associée à un risque plus important de SM chez les hommes et les femmes postménopausées : Odds ratio (OR) et [intervalle de confiance à 95%] pour la ferritine 1.44 [1.07-1.94] et 1.47 [0.99-2.17]; pour la Tsf et la CTF, OR=1.43 [1.06-1.91] et 2.13 [1.44-3.15] pour les hommes et les femmes postménopausées, respectivement. Au contraire, l'appartenance au quartile le plus élevé de la SaTsf était associé à un risque moins important de SM: OR=0.77 [0.57-1.05] et 0.59 [0.39-0.90] pour les hommes et les femmes postménopausées, respectivement. Il n'y avait aucune association entre les marqueurs sanguins du métabolisme du fer et le SM chez les femmes préménopausées, ni entre le fer sanguin et le SM chez les trois groupes. En conclusion, la majorité des marqueurs sanguins du métabolisme du fer, mais pas le fer lui-même, sont associés de manière indépendante au SM chez les hommes et les femmes postménopausées. -- Context: Excessive iron storage has been associated with metabolic syndrome (MS). Objective: To assess the association between markers of iron metabolism and MS in a healthy population. Design: Cross-sectional study conducted between 2003 and 2006. Setting: Population-based study in Lausanne, Switzerland. Patients: 5,498 participants aged 35-75 years, stratified by sex and menopausal status. Participants with transferrin saturation (TSAT) >50% were excluded. Intervention: None. Main Outcome Measures: serum iron, ferritin, transferrin, total iron binding capacity (TIBC) and TSAT. MS was defined according to ATP-III criteria. Results: Prevalence of MS was 29.4% in men, 8.3% in premenopausal and 25.5% in postmenopausal women. On bivariate analysis, the highest prevalence of MS occurred in the highest quartiles of serum ferritin, transferrin and TIBC, and in the lowest quartile of TSAT. After multivariate adjustment for age, body mass index, C-reactive protein, smoking, alcohol, liver markers and iron supplementation, men and postmenopausal women in the highest quartile of serum ferritin, transferrin and TIBC had a higher risk of presenting with MS: for ferritin, Odds ratio and [95% CI]=1.44 [1.07-1.94] for men and 1.47 [0.99-2.17] for postmenopausal women; for transferrin and TIBC, OR=1.43 [1.06-1.91] and 2.13 [1.44-3.15], Participants in the highest quartile of TSAT had a lower risk of MS: OR=0.77 [0.57-1.05] for men and 0.59 [0.39-0.90] for postmenopausal women. No association was found between iron and MS and between markers of iron metabolism and MS in premenopausal women. Conclusion: Ferritin, transferrin, TIBC are positively and TSAT is negatively associated with MS in men and postmenopausal women.

Effects of oral supplementation of iron on hepcidin blood concentrations among non-anaemic female blood donors: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Hepcidin is the main hormone that regulates iron balance. Its lowering favours digestive iron absorption in cases of iron deficiency or enhanced erythropoiesis. The careful dosage of this small peptide promises new diagnostic and therapeutic strategies. Its measurement is progressively being validated and now its clinical value must be explored in different physiological situations. Here, we evaluate hepcidin levels among premenopausal female donors with iron deficiency without anaemia. MATERIALS AND METHODS: In a preceding study, a 4-week oral iron treatment (80 mg/day) was administered in a randomized controlled trial (n = 145), in cases of iron deficiency without anaemia after a blood donation. We subsequently measured hepcidin at baseline and after 4 weeks of treatment, using mass spectrometry. RESULTS: Iron supplementation had a significant effect on plasma hepcidin compared to the placebo arm at 4 weeks [+0·29 nm [95% CI: 0·18 to 0·40]). There was a significant correlation between hepcidin and ferritin at baseline (R(2) = 0·121, P < 0·001) and after treatment (R(2) = 0·436, P < 0·001). Hepcidin levels at baseline were not predictive of concentration changes for ferritin or haemoglobin. However, hepcidin levels at 4 weeks were significantly higher (0·79 nm [95% CI: 0·53 to 1·05]) among ferritin responders. CONCLUSIONS: This study shows that a 4-week oral treatment of iron increased hepcidin blood concentrations in female blood donors with an initial ferritin concentration of less than 30 ng/ml. Apparently, hepcidin cannot serve as a predictor of response to iron treatment but might serve as a marker of the iron repletion needed for erythropoiesis.

Effect of adsorbed polyaniline on the thermal stability of iron and arsenic oxides

Iron and arsenic oxide grains are coated with the conducting organic polymer polyaniline. The obtained samples were characterized by infrared spectroscopy, SEM, conducting measurements and thermogravimetry. The thermal stability of both oxides are increased. For As2O3 the sublimation temperature is increased from 165ºC in the pure oxide to 206ºC in the polymer modified sample. The pure Fe3O4 sample exhibits sublimation at 780ºC whereas the polyaniline coated oxide is stable until at least 1000ºC.

Design and production of protein nanostructures for biomolecular detection

Particulate nanostructures are increasingly used for analytical purposes. Such particles are often generated by chemical synthesis from non-renewable raw materials. Generation of uniform nanoscale particles is challenging and particle surfaces must be modified to make the particles biocompatible and water-soluble. Usually nanoparticles are functionalized with binding molecules (e.g., antibodies or their fragments) and a label substance (if needed). Overall, producing nanoparticles for use in bioaffinity assays is a multistep process requiring several manufacturing and purification steps. This study describes a biological method of generating functionalized protein-based nanoparticles with specific binding activity on the particle surface and label activity inside the particles. Traditional chemical bioconjugation of the particle and specific binding molecules is replaced with genetic fusion of the binding molecule gene and particle backbone gene. The entity of the particle shell and binding moieties are synthesized from generic raw materials by bacteria, and fermentation is combined with a simple purification method based on inclusion bodies. The label activity is introduced during the purification. The process results in particles that are ready-to-use as reagents in bioaffinity. Apoferritin was used as particle body and the system was demonstrated using three different binding moieties: a small protein, a peptide and a single chain Fv antibody fragment that represents a complex protein including disulfide bridge.If needed, Eu3+ was used as label substance. The results showed that production system resulted in pure protein preparations, and the particles were of homogeneous size when visualized with transmission electron microscopy. Passively introduced label was stably associated with the particles, and binding molecules genetically fused to the particle specifically bound target molecules. Functionality of the particles in bioaffinity assays were successfully demonstrated with two types of assays; as labels and in particle-enhanced agglutination assay. This biological production procedure features many advantages that make the process especially suited for applications that have frequent and recurring requirements for homogeneous functional particles. The production process of ready, functional and watersoluble particles follows principles of “green chemistry”, is upscalable, fast and cost-effective.

Novel neutral iron(II) isocyanide maleonitrile dithiolate [Fe(S2C2(CN)2)(t-BuNC) 4] compound

FeBr2 reacts with the S2C2(CN)2(2-) ion (1:1 ratio) in the presence of an excess of t-BuNC in THF to give the mixed ligand [Fe(S2C2(CN)2)(t-BuNC) 4] compound. This neutral product with a formal oxidation state of two for the iron atom was characterized by conductivity measurements, and, i.r., Mössbauer, 13C and ¹H n.m.r. spectroscopy. There is a Fe-C pi back-donation strengthened towards isocyanide ligands, according to the data of 13C, ¹H n.m.r. and Mössbauer spectroscopy.

Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV) chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II) and iron(III) ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water). The procedure was successfully applied to natural waters and human hair.

Iron oxide and pyrocatechol: a spectroscopy study of the reaction products

The reaction of 1,2-dihydroxy-benzene (pyrocatechol) (C6H6O2) with iron oxide (Fe2O3) and sodium thiosulfate (Na2S2O3) in aqueous medium (pH 7) was investigated. Pyrocatechol suffers autoxidation and coordinates with Fe3+ in solution. The presence of S2O3(2-) in solution was fundamental to generate and stabilize the pyrocatechol oxidation products as o-semiquinones. This compound was isolated and its structure characterized using FT-IR, EPR and UV-Vis Spectroscopy as [CTA][Fe(SQ)2(Cat)]. A thermal mass loss mechanism was proposed based on Thermogravimetric Analysis (TG) to support the structural characterization.