341 research outputs found
Se-speciation investigations at neural barrier (NB)
No full textIntroduction: Se-speciation helps for deeper insight into Se-metabolism and transport, important at NB or under
neurological diseases. Analytical set-up of hyphenated speciation techniques with 2-D-identification of Se-compounds
is described. Then applications at NB in paired serum and cerebrospinal fluid (CSF) samples are reported, finishing
with comparison of Se-speciation of neurologically diseased persons vs. controls.
Method: Serum and CSF samples were subject to speciation analysis by HPLC-ICP-DRC-MS. For improved species
identification Se-species were analysed serially after HPLC by CE-ICP-DRC-MS (2D approach).
Result: Paired samples had 58.39 (serum) or 0.86 (CSF , each μg Se/L). Prominent Se-species were selenoprotein-P
(SePP), glutathione-peroxidase (GPx), thioredoxinreductase (TrxR), Se(IV) and Se-albumin (Se-HSA).
Relationships between Se-species from serum and CSF allowed evaluating Se-species passage across NB: SePP-serum
correlated with total Se-serum when > 65 μg/L. SePP-CSF appeared independent from SePP-serum. For anti-oxidative Seenzymes
higher correlation factors (r2) were calculated: GPx-serum/GPx-CSF: r2=0.3837 and TrxR-serum/TrxR-CSF:
r2=0.6293. No correlation for inorganic Se-compounds was found proving limited representativeness of their circulating
levels beyond NB[1].
Se-species-ratios (CSF/serum) were 21.4*10-3 (TrxR) or 8.3*10-3 (GPx), being significantly elevated compared to NB
permeability factor 3.8*10-3 (HSA).
In a hospital-referred cases-control we investigated Se-species in CSF of patients with amyotrophic lateral sclerosis,
compared to reference neurological patients. We found an excess concentration of inorganic Se(IV) and reduced levels
of organic Se-compounds among ALS patients[2].
Discussion: ROS-protecting enzymes GPx and TrxR seem to be shuttled across NB to brain/CSF. In ALS etiology
overexposure of inorganic Se(IV) together with decreased organic Se-species may be involved in ALS etiology
Color Metaphors by Alexander Solovyev
No full textВ статье рассматриваются вопросы творчества одного из выдающихся белорусских художников Александра Александровича Соловьева, который несколько десятилетий работал главным художником-постановщиком театра имени Якуба Коласа в Витебске и является представителем традиции Витебской художественной школы. Авангардные идеи он поддерживал и пропагандировал еще в 1960-е годы, когда об авангарде говорить было опасно. Блестяще образованный, эрудированный, разносторонний в художнической деятельности,
А. Соловьев аккумулировал в Витебске идеи современного художественного мышления не только в рамках сценического пространства, но и участвуя в разнообразных выставках изобразительного искусства. Автор статьи сосредотачивает свое внимание на проблемах сценографии А. Соловьева. Оформленные им спектакли вошли в историю сценическом творчестве, в модернистском направлении художественной культуры.
Issues of creative work of one of the outstanding Belarusian artists Alexander Solovyev, who was Chief Artist Director at Vitebsk Yakub Kolas Theater for decades and is a representative of Vitebsk art school tradition, are considered in the article. He supported and promoted vanguard ideas already in the 1960-ies when it was dangerous to speak about vanguard. Brilliantly educated intellectual, manifold in his creative activity A. Solovyev accumulated in Vitebsk ideas of modern artistic thinking not only within stage space but also participating in different fine art exhibitions. The author of the article concentrates his attention on the issues of scenography of A. Solovyev. Performances, decorated by him, entered the history of national theatrical art as patterns of new thinking in stage art, in modernist direction of art culture
Trace element species and amyotrophic lateral sclerosis with disease associated genetic mutations
No full textIntroduction: Amyotrophic lateral sclerosis (ALS) is a motor neuron disease with mostly unknown eti-ology. Certain genetic mutations are associated with the disease; however, the role of environmental factors, such as exposure to metals and organic pollutants is also widely discussed in the literature. ALS, as other neurodegenerative disorders, is related to the brain oxidative stress, so the disturbance of redox homeostasis may be anticipated for such elements as selenium (Se), copper (Cu), iron (Fe), and manganese (Mn).
Aim: The aim of the study was to evaluate a possible alteration of trace element (Se, Cu, Mn, and Fe) homeostasis in the ALS patients with disease associated gene mutations.
Methods: We analyzed cerebrospinal fluid (CSF) samples from 9 patients with ALS-associated muta-tions (C9ORF72, SOD1, FUS, TARDBP, ATXN2, and TUBA4A) and 42 age- and gender-matched controls. Advanced speciation techniques were used to quantify redox forms of Cu (I/II), Mn (II/III), and Fe (II/III) and Se species (selenoprotein P, glutathione peroxidase, thioredoxin reductase, selenite, selenate, and human serum bound-Se). For the separation of Se species strong anion exchange chromatography (SAX) was used, whereas Cu, Mn, and Fe redox forms were separated by strong cation exchange (SCX). For the species detection, inductively coupled plasma sector field mass spectrometry (ICP-sf-MS), op-erated at high resolution for Se or medium resolution for Cu, Fe, and Mn was employed. Standard compounds and spikings were used for peak assignment. External calibration vs. matching to the total content of the elements, measured by inductively coupled plasma dynamic reaction cell mass spec-trometry, was used for species quantification.
Results: The analytical schemes of species quantification, using SAX-ICP-sf-MS [1] and SCX-ICP-sf-MS [2], have been optimized. The difference in Cu(II) and some Se species were found to be altered in the CSF of the ALS patients with disease-associated mutations. Also, since multi-element speciation had been performed for the same set of CSF samples, some inter-element correlations were observed (be-tween Fe and Se species, Mn and Fe, Mn and Cu).
Conclusion: Despite the limited sample size, we could presume a distortion in trace element metabo-lism, reflected the altered speciation of Cu and Se in the CSF. However, more insight is required to understand if these findings are an innocent bystander to the pathological changes in the ALS brain or has its own relevant role in the etiopathogenesis of the disease
Redox speciation of iron, manganese, and copper in cerebrospinal fluid by strong cation exchange chromatography – sector field inductively coupled plasma mass spectrometry
No full textAbstract
A new method of simultaneous redox speciation of iron (II/III), manganese (II/III), and copper (I/II) in cerebrospinal fluid (CSF) has been designed. For the separation of redox species strong cation exchange chromatography (SCX) with isocratic elution was employed. Species were detected using inductively coupled plasma sector field mass spectrometry (ICP-sf-MS), operating at medium resolution. The following parameters were optimized: analytical column, eluent composition and pH, CSF injection volume and dilution factor. Analytical column Dionex IonPac CS5A RFIC 4*250 mm was found to retain and separate species of interest the most effectively under the isocratic elution with a buffer, containing 50 mM ammonium citrate, 7.0 mM pyridine-2,6-dicarboxylic acid at pH = 4.2 and flow rate of 0.8 L min−1. Injection volume of 50 μL with CSF sample dilution of 1/3 (v/v) with the eluent was shown to result in minimal matrix suppression. For species identification, retention time matching with standards was used. The stability of metalloproteins (ferritin, transferrin, and ceruloplasmin) under elution conditions was evaluated. For the quantification of redox species, external calibration was employed. To avoid column contamination, a blank was run after measurement and all quantification values were blank subtracted. For recovery checks, species quantification data was verified against total content of an element, measured by dynamic reaction cell ICP-MS. Recoveries (sum of quantified species vs. total element determinations) were 82.5 ± 22% (Mn), 92 ± 11% (Fe), and 88.7 ± 12% (Cu). The method was tested using 38 real CSF samples. Limits of detection (3σ) for the CSF samples were 0.5 μg L−1, 0.6 μg L−1, and 0.8 μg L−1 for Fe, Mn, and Cu species, respectively. Retention time precision was 1–7.5% (as RSD), whereas peak area RSDs were in the range 5–11%, both depending on the species
Selenoprotein P and its potential role in Alzheimer's disease
No full textAlzheimer's disease (AD) is the most common neurodegenerative disease associated with cognitive decline, loss of memory, and progressive cerebral atrophy. The trace element selenium (Se) is known to be involved in brain pathology. Selenoprotein P (SELENOP), as the main Se transport protein, is, to a great extent, responsible for maintaining Se homeostasis and the hierarchy of selenoprotein expression in the body. Adequate Se supply through SELENOP is vital for proper brain development and function. Additionally, SELENOP may be implicated in pathological processes in the central nervous system, including those in AD. The current review summarizes recent findings on the possible role of SELENOP in AD, with a focus on probable mechanisms: Se delivery to neurons, antioxidant activity, cytoskeleton assembly, interaction with redox-active metals (e.g., copper and iron), and misfolded proteins (amyloid beta and tau protein). The use of SELENOP as a biomarker of Se status is also briefly discussed. Epidemiological studies on Se supplementation are beyond the scope of the current review
Direct determination of beryllium, cadmium, mercury, lead and thallium in whole blood by Zeeman modulation polarization spectrometry
No full textA methodic approach for determination of beryllium, cadmium, mercury, lead and thallium in whole blood without preliminary sample digestion based on Zeeman modulation polarization spectrometry has been proposed. Using of this type of selective atomic absorption spectrometry simultaneously with individual optimization of surface and matrix modification, furnace programs and sample dilution allowed coping effectively for both spectral and matrix-based interferences
Aleksandar Soloveov as an investigator of Baltazar Bogisic's heritage and of legal and historical documents from the 15th till the 19th century
No full textThis paper discusses Aleksandar Solovyev?s research which he primarily carried out in Bogisic?s archive in Cavtat, as well as the research including other sources relevant for the legal history of our nation in the Dubrovnik region, in other coastal areas and in the countries in their immediate hinterland; all the documents belong to the period from the 15th till the 19th century. Although he discovered most of these documents in Bogisic?s archive, Solovyev got documents from other sources, too. Solovyev published the greatest part of these materials in the editions of The Serbian Royal Academy, but he also published some treatises and articles in the following magazines: Arhiv za pravne i drustvene nauke, Godisnjica Nikole Cupica and some others. Furthermore, the author particularly underlines the fact that Solovyev - in his introductory texts accompanying his publications - also did the scientific and critical analysis of the collected historical material. Studying Bogisic?s archive in Cavtat, Solovyev also got interested in the very personality of Baltazar Bogisic. In his articles in Arhiv za pravne i drustvene nauke, Solovyev particularly presented his discoveries about Bogisic?s archive, he also found an unknown manuscript of Bogisic?s, the one about a law project written for the rebels from Herzegovina when they rose against the Turks for the liberation of the Serbian nation in 1875. In his collaboration with the Herzegovian rebells, Bogisic expressed his Serbian patriotic feelings, too. As for his nationality, Bogisic felt to be a Serb (?a Serb catholic?, as he used to say), but also a member of the South Slavic nation. Thus Solovyev in one of his articles (in French) described Bogisic?s activity in the elaboration of the law projects for the newly liberated Bulgaria, which remained less known in our country. Discussing Bogisic?s patriotic activity, too, the author also presents other facts about his nationality. Although the results of Solovyev?s research work discussed in this paper were available to our scientific public, our scholars have not written about them so far.</jats:p
The study of levels from redox-active elements in cerebrospinal fluid of amyotrophic lateral sclerosis patients carrying disease-related gene mutations shows potential copper dyshomeostasis.
No full textAmyotrophic lateral sclerosis is a progressive neurodegenerative disease characterized by a loss of function of motor neurons. The etiology of this disorder is still largely unknown. Gene-environment interaction arises as a possible key factor in the development of amyotrophic lateral sclerosis. We assessed the levels of trace metals, copper (Cu), iron (Fe), and manganese (Mn), of 9 amyotrophic lateral sclerosis cases and 40 controls by measuring their content in cerebrospinal fluid. The following trace element species were quantified using ion chromatography-inductively coupled plasma mass spectrometry: univalent copper (Cu-I), divalent Cu (Cu-II), divalent Fe (Fe-II), trivalent Fe (Fe-III), divalent Mn (Mn-II), trivalent Mn (Mn-III), and also unidentified Mn species (Mn-unknown) were present in some samples. When computing the relative risks for amyotrophic lateral sclerosis through an unconditional logistic regression model, we observed a weak and imprecise positive association for iron (Fe III, adjusted odds ratio 1.48, 95% CI 0.46-4.76) and manganese (total-Mn and Mn-II; adjusted odds ratio 1.11, 95% CI 0.74-1.67, and 1.13, 95% CI 0.79-1.61, respectively). Increased risk for copper was found both in the crude analysis (odds ratio 1.14, 95% CI 0.99-1.31) and in multivariable analysis after adjusting for sex, age, and year of storage (1.09, 95% CI 0.90-1.32). Our results suggest a possible positive association between Cu and genetic amyotrophic lateral sclerosis, while they give little indication of involvement of Fe and Mn in disease, though some correlations found also for these elements deserve further investigation
Cerebrospinal fluid of newly diagnosed amyotrophic lateral sclerosis patients exhibits abnormal levels of selenium species including elevated selenite.
No full textExposure to selenium, and particularly to its inorganic forms, has been hypothesized as a risk factor for amyotrophic lateral sclerosis (ALS), a fast progressing motor neuron disease with poorly understood etiology. However, no information is known about levels of inorganic and some organic selenium species in the central nervous system of ALS patients, and recent observations suggest that peripheral biomarkers of exposure are unable to predict these levels for several Se species including the inorganic forms. Using a hospital-referred case-control series and advanced selenium speciation methods, we compared the chemical species of selenium in cerebrospinal fluid from 38 ALS patients to those of 38 reference neurological patients matched on age and gender. We found that higher concentrations of inorganic selenium in the form of selenite and of human serum albumin-bound selenium were associated with increased ALS risk (relative risks 3.9 (95% confidence interval 1.2-11.0) and 1.7 (1.0-2.9) for 0.1μg/L increase). Conversely, lower concentrations of selenoprotein P-bound selenium were associated with increased risk (relative risk 0.2 for 1μg/L increase, 95% confidence interval 0.04-0.8). The associations were stronger among cases age 50 years or older, who are postulated to have lower rates of genetic disease origin. These results suggest that excess selenite and human serum albumin bound-selenium and low levels of selenoprotein P-bound selenium in the central nervous system, which may be related, may play a role in ALS etiology
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