Stasys Tautkus

Biocompatibility of polypyrrole particles: an in-vivo study in mice

The objectives of this study were the chemical synthesis of polypyrrole particles, the investigation and estimation of the impact of polypyrrole particle concentration, and the evaluation of the effect of duration of treatment on immune‐related haematological parameters and peritoneum cells in mice. The results showed that chemically prepared polypyrrole particles did not have any detectable cytotoxic effect on mouse peritoneum cells. Polypyrrole particles did not induce any allergic response, nor did they affect spleen, kidney or liver indexes. Moreover, no effect of polypyrrole particles on immune‐related haematological parameters was observed. No inflammation was detected in the peritoneum of mice after a 6‐week period of treatment with polypyrrole particles. In conclusion, chemically synthesized polypyrrole particles showed good biocompatibility in mice and are attractive candidates for biomedical applications in‐vivo.

Thermogravimetric analysis — a powerful tool for the refinement of the synthesis process of Hg-based superconductors

The paper presents the results of studies on thermogravimetric (TG) characterization of precursors and Hg-based superconductors synthesized by the sol-gel method. TG experiments were performed in an oxygen flow in order to understand the decomposition mechanisms of the fabricated gels and to determine the synthesis temperature of the intermediate precursors for the HgBa(2)CaCu(2)O(6+delta), HgBa(2)Ca(2)Cu(3)O(8+delta), and Hg(1-x)Tl(x)Ba(2)Ca(2)Cu(3)O(8+delta) superconductors. The optimum annealing temperature for a desired oxygen content in the superconducting compounds has been established by thermogravimetric measurements. To assist the interpretation of the obtained results the elemental analyses of the synthesized products were performed by AAS and EDS (SEM) methods.

Residual content of inorganic ions in activated carbons prepared from wood

Abstract The content and redistribution of inorganic ions (calcium, magnesium, potassium and sodium) among the activated carbon (AC) samples, produced from wood in the laboratory, was determined by means of atomic absorption spectrometry. Three of those elements (Ca, Mg and K) are considered as biogenic. Calcium and Na might be introduced during the process of AC preparation. Content of surface functional groups was determined using a potentiometric titration. Effect of preparation conditions on the distribution of inorganic ions was evaluated. It is established that the high temperature raising rates in temperature zone above 500 K most probably favors the formation of closed pores, which are inaccessible to the leaching reagents. At the same time, both high temperature raising rates below 500 K and the thermal shock are favorable to the formation of open-pore structure. Close correlation between K and Na residual content in ACs is established. It is also found that residual amount of Mg stands in inverse correlation with amount of lactone and phenol functional groups on the surface of AC samples.

Investigation of Distribution of Heavy Metals between Blood Plasma and Blood Cells

The physiological importance of metals in human organism has been shown by many publications. The toxic doses of metals and their compounds can lead to serious health problems.1–4 Different metals present in the composition of blood can form different complexes with many organic compounds and biomolecules which could be found in the body fluids.5–7 Depending on the concentration of metals in the parts of body, different metal-ligand equilibriums could be established in the system. These changes could cause changes in global bioprocesses, or different clinical symptoms and metabolic stresses in human organism could occur. The distribution of metals between blood plasma and blood cells could represent an important clinical index.8–10 The aim of the present study was to investigate, for the first time to our knowledge, the distribution of heavy metals between blood plasma and cells in the blood samples from the infected by hepatitis C and non-infected patients.

Determination of Trace Elements in Adipose Tissue of Obese People by Microwave-Assisted Digestion and Inductively Coupled Plasma Optical Emission Spectrometry

In the present work, analytical method for the determination of trace elements in adipose tissue by means of inductively coupled plasma optical emission spectrometry (ICP-OES) was developed. Adipose tissue from two groups of the patients with obesity (with and without metabolic syndrome) was investigated. The main aim of this study was to reveal some differences and regularities in concentrations of trace elements in adipose tissue between these two groups of the individuals. Moreover, different types of adipose tissue (subcutaneous, preperitoneal, and visceral) were analyzed separately in order to investigate distribution of metals between these types in different groups of obese people. Al, Ba, Ca, Co, Cu, Cr, Fe, K, Li, Mg, Mn, Na, Ni, Sr, and Zn were selected for the quantitative determination. However, only 6 elements (Na, K, Ca, Fe, Mg, and Zn) were determined in all analyzed samples independently of the type of adipose tissue and presence of metabolic disorder of the patient. Concentrations of Ca, Fe, K, and Na were found to be strongly dependent on the type of adipose tissue. Other elements in terms of detection frequency in adipose tissue samples can be arranged in the following sequence Sr (94.7%), Cr (86.2%), Cu (24.6%), Li (18%), Ba (1.8%), Co (0.05%). The concentrations of Al, Mn, and Ni were found to be lower than limit of detection (LOD) in all analyzed samples. Comparison of metal distribution depending on the type of adipose tissue of people with and without metabolic syndrome is discussed in this work.

Response of Test-Organisms to Different Na and Cu Salts

Abstract The scope of this research involves the evaluation of biological impact of different Na and Cu salts (nitrates, sulphates and chlorides) on test-organisms. The toxic impact of Na and Cu salts on seed germination and root growth of Lepidium sativum (garden-cress) as well as mortality, growth and physiological parameters of On-corhynchus mykiss (rainbow trout) in early development stages (embryos and larvae) were determined. Among Na salts, nitrate was the most toxic to both test-organisms. Among tested Cu salts, sulphate caused the strongest toxic impact on L. sativum and nitrate - on embryos and larvae of O. mykiss. The accumulation of all tested anions and cations from the solutions of tested salts was higher in roots than in shoots ofL. sativum. The highest transfer of Na+ and Cu2+ from roots to shoots was determined for plants cultivated in sulphate salt. The transfer of SO4 2” was the highest among tested anions of sodium salts and the transfer of NO3” was higher among tested anions of copper salts. The rather high correlation was found between root length and amount of Na+, NO3” and SO4 2” ions in plant roots and rather low correlation coefficient was calculated between root length and the amount of Na+ and Cl” ions in roots.

Impact on porcine heart valve tissue treating with carbodiimide

Summary Objectives: There are many treatment protocols used these days, but seems like no one ensures a hundred percent effectiveness for lifelong prosthesis function. The aim of the study was to investigate whether some new method could mitigate calcification better than usually used and to compare impact on different valve tissues. Methods: Porcine aortic and mitral valve cusps were treated with glutaraldehyde and carbodiimide. Control group without any treatment was also used. Cusp pieces were implanted subcutaneously into 90 rats for 60 days. Tissue calcification was assessed by atomic absorption spectrophotometry. Results: The most calcification was found when not used any treatment, and the lowest calcium level was in group when treated with carbodiimide. Glutaraldehyde in low concentration lowered significantly residual calcium level, but not so effectively as carbodiimide. All data differ statistically significantly (p < 0.05). Conclusion: Calcification was minimal treating porcine valve tissue with carbodiimide comparing to glutaraldehyde or no treatment.