35 research outputs found
Investigation of climate change and history of lead deposition using soil archives
Our study focused on the investigation of climate change and the fate of lead in soils from the Low Volga region of Russia over 3500 years. We used a comparative analysis of the modern soils and palaeosols preserved under burial mounds, which date back to the Middle Ages and the Early Iron and Bronze Ages. A climate reconstruction showed periodic changes, with the most humid climate conditions occurring during Golden Horde period. However, we could not find any consistent changes in Pb concentration and profile distribution following the climate change. We observed a clear difference in Pb isotopic ratios between the lower and upper horizons both for the modern and buried profiles, reflecting the influence of atmospheric lead depositions. However, there is no statistically significant difference in Pb isotopic ratios between the upper horizons of buried and modern soils (except modern soils collected in the vicinity of a motorway). This means that either anthropogenic input due to long range air transport was insignificant, or that airborne anthropogenic lead and natural airborne lead have similar isotopic composition
Validation of transfer functions predicting Cd and Pb free metal ion activity in soil solution as a function of soil characteristics and reactive metal content.
According to recent insight, the toxicity of metals in soils is better related to the free metal ion (FMI) activity in the soil solution than to the total metal
concentration in soil. However, the determination of FMI activities in soil solution is a difficult and time-consuming task. An alternative is to use empirical equations (so called transfer functions (TFs)) that relate FMI activity in solution to the reactive metal concentration in the solid phase and to soil properties (pH and organic matter content). Here we test the applicability of two sets of TF for Cd and Pb using independent data from a wide range of soil types and regions that are not represented in the datasets used to derive the TFs. From these soils, soil solution was extracted using four different methods. For all these extracts, FMI activities were calculated from total concentrations in solution using the speciation program WHAM VI. In some of the soils, Cd and Pb FMI activities
were also measured using a Donnan membrane technique. Most of these FMI activities deviated from the TF predictions by less than one order of magnitude and were within the 95% confidence interval of the TFs, irrespective of the
method used to extract soil solution. Predictability was higher for Pb than for Cd and differed also between the two TF sets
Food labelling and food-induced anaphylaxis in children. Where are the intersection points?
Anaphylaxis is an acute life-threatening condition affecting several body systems. It might have a rapid onset and lead to a lethal outcome. The major provoking factors for the development of anaphylactic reactions in childhood are food allergens. High hypersensitivity to one food allergen can make it difficult for a family to find a substitution for an allergenic product. Food-induced anaphylactic reaction to quite a number of food allergens is a serious problem for both the physician and the family of an allergic child necessitating organization of appropriate and safe nutrition. In real life, the standard recommendation for the patient – to strictly follow the rules of the elimination diet with exclusion of the causative allergen and all cross-reactive allergens – often becomes unrealizable. There is a serious risk of developing new allergic reactions due to accidental intake of the triggering allergens because of incorrect food labelling by manufacturers. The objective of the work is to present a clinical case report that demonstrates the importance of performing allergy component testing (ImmunoCAP ISAC-112,) for identification of the full spectrum of allergens with subsequent assessment of allergenic molecules as triggering allergens and shows serious difficulties in the elaboration of recommendations on a personalised diet that should be adequate and safe for a child with a history of recurrent episodes of food-induced anaphylaxis.Анафилаксия – острое жизнеугрожающее состояние, затрагивающее несколько систем организма, которое может развиться мгновенно и привести к фатальному исходу. Основными провоцирующими факторами развития анафилактических реакций в детском возрасте являются пищевые аллергены. При выраженной гиперчувствительности к одному пищевому аллергену возникают сложности для семьи в плане замены виновного продукта. Наличие же пищевой анафилаксии к большому числу пищевых аллергенов – это серьезная проблема для врача и семьи пациента по организации полноценного и безопасного питания ребенка. В реальной жизни обязательная рекомендация для пациента – придерживаться жестких правил элиминационной диеты с исключением причинно-значимого аллергена и всех перекрестных с ним аллергенов – зачастую становится просто невыполнимой. Серьезный риск возникновения новых аллергических реакций существует при случайном попадании в организм аллергенов-триггеров из-за неоднозначности маркировки пищевых продуктов при изготовлении этикеток на продуктах питания. Цель работы: представить клинический случай, демонстрирующий важность проведения компонентного аллергологического обследования (ISAC-112, ImmunoCAP) для выявления полного спектра аллергенов с дальнейшей оценкой аллергенных молекул как аллергенов-триггеров и раскрывающий серьезные трудности в разработке рекомендаций по индивидуальной лечебной диете, которая должна быть полноценной и безопасной для ребенка с повторными эпизодами пищевой анафилаксии в анамнезе
АТОПИЧЕСКИЙ ДЕРМАТИТ У ДЕТЕЙ: НАЛИЧИЕ СПЕЦИФИЧЕСКИХ АНТИТЕЛ К СУПЕРАНТИГЕНАМ STAPHYLOCOCCUS AUREUS И ЕГО АНТИБИОТИКОРЕЗИСТЕНТНОСТЬ
Background. Staphylococcus aureus function in atopic dermatitis (AD) children skin is double-handed: an infectious trigger and an allergen. The aim of the study was to evaluate the frequency of S. aureus enterotoxins the IgE in children with infected AD skin and to compare the IgE levels with antibiotic resistance of S. aureus. Methods: specific IgE to S. aureus enterotoxins A and B (ImmunoCap, Phadia AB, Sweden) were detected in the serum of 90 children infected with AD. The IgE levels were compared with the resistance to antibiotics (McNemar test and 95% confidential intervals of related frequencies). Results: specific IgE > 0,35 kUA/l to S. aureus enterotoxin A were found with a frequency of 0,29; to enterotoxin B — 0,36; to at least one of them — 0,43. The number of children with IgE > 0,35 kUA/l and S. aureus resistant to antibiotics was about 1/3 of the number of children with IgE < 0,35 kUA/l and S. aureus sensitive to antibiotics (р < 0,001). S. aureus in children with IgE > 0,35 kUA/l remained sensitive to oxacillin. Conclusion. In children infected with AD S. aureus enterotoxins A or/and B are revealed in 25–50% of cases. Specific IgE levels to S. aureus enterotoxins are similar in antibiotic resistant and antibiotic sensitive S. aureus skin swabs — about 30%. The IgE level to enterotoxins of S. aureus and its antibiotic resistance don't seem to be conditioned by each other.Актуальность. Наличие атопии создает условия для функционирования Staphylococcus aureus не только в качестве триггера инфекционного процесса, но и в качестве аллергена. Цель работы — оценить частоту выявления специфических IgE к энтеротоксинам S. aureus кожи детей с атопическим дерматитом (АтД), осложненным вторичным инфицированием кожи, и сопоставить наличие IgE с антибиотикорезистентностью S. aureus. Пациенты и методы. Обследовано 90 детей с АтД, осложненным вторичным инфицированием кожи. Специфические IgE-антитела к энтеротоксинам А и В S. aureus определяли иммунохемилюминесцентным методом (ImmunoCap, Phadia AB, Швеция). Оценивали взаимосвязь наличия IgE к энтеротоксинам S. aureus с его антибиотикорезистентностью (критерий МакНемара, 95% доверительные интервалы относительных частот). Результаты. Специфические IgE к энтеротоксину А обнаружены с частотой 0,29, к энтеротоксину В — 0,36, хотя бы к одному из них — 0,43. Количество детей с наличием специфических IgE и устойчивыми к антибиотикам штаммами S. aureus составляло 1/3 количества детей с отсутствием IgE и чувствительными штаммами S. aureus (р < 0,001). Заключение. У детей с АтД, осложненным вторичной инфекцией, энтеротоксины А и/или В S. aureus обнаруживаются в 25–50% наблюдений. Частота выявления IgE к энтеротоксинам S. aureus одинакова у штаммов с различной антибиотикорезистентностью и составляет 30%. Взаимной опосредованности антибиотикорезистентности S. aureus и выработки специфических IgE-антител к его энтеротоксинам не выявлено
Validation of Transfer Functions Predicting Cd and Pb Free Metal Ion Activity in Soil Solution as a Function of Soil Characteristics and Reactive Metal Content
Lead content and isotopic composition in submound and recent soils of the Volga upland
Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead
Comparison of methods for copper free ion activity determination in soil solutions of contaminated and background soils
In many cases bioavailability and toxicity of cationic metals in soils is determined by the free metal ion (FMI) activity in soil solution. Recently methods were developed that relate biological effects to FMI activity. The use, validation and further development of such approaches require determination of FMI activities in soil. FMI activity determination is, however, prone to methodological and analytical problems. Therefore we tested two different analytical methods: Cu activity measurement with (1) an ion selective electrode (ISE) and (2) a Donnan Membrane Technique (DMT). In addition we used computational methods to predict copper activity: (1) using speciation models WHAM VI and NICA and (2) using transfer functions (TF) which relate metal partitioning to soil properties. Methods were tested on soils contaminated with Cu by a Cu-Ni smelter. Emphasis was given to the organic horizon because of its importance for soil life and because FMI data for this horizon are lacking. Results show good agreement between Cu activities measured with Cu-ISE and DMT for the high Cu concentration range. The use of ISE method was limited to solutions with total Cu concentrations above 10¿6 mol¿L¿1, below this concentration the method gave unreliable results. The DMT technique was limited by the detection limit of the ICP-MS used (10¿8 mol¿L¿1). Deviation between models (WHAM, NICA, and TF) and measurements are within uncertainties due to different analytical techniques and the spatial variation found in soils
Specific features of sensitization to recombinant peanut allergens in children with anaphylaxis
Molecular allergy diagnosis makes it possible not only to identify allergic sensitization to peanut as a whole, but also to establish the specific allergen the specific IgE is synthesized to. The purpose of this study was to establish a relationship between sensitization to certain molecules of peanut and allergy as anaphylaxis after eating the product. An immunofluorescence assay (Immuno CAP 100 Phadia AB, Switzerland) was used to determine specific IgE to whole allergen in the peanut and its components (Ara h1, Ara h2, Ara h3, Ara h8, and h9 Ara). Children diagnosed with peanut-induced anaphylaxis were found to be significantly more sensitized to the recombinant allergens Ara h8 and Ara h9 (p=0.019). The detected combination of sensitization to the recombinant peanut allergen Ara h8 and Ara h9 indicates a high probability that an allergic reaction may manifest as anaphylaxis. Determination of specific IgE against peanut proteins will optimize patient management tactics