Kinetics of polymerization of mixed diacetylene single crystals determined from dielectric measurements

Results of investigations on the kinetics of thermal polymerization of mixed single-crystalline diacetylenes are reported. The polymerization was studied at 333 K on a series of mixed 1 (pTS)– 3 (pFBS) crystals of various compositions. The polymer contents were determined from the measurements of electric permittivities of the samples during polymerization. A simple qualitative model was put forward to explain changes in the kinetics of polymerization as function of the composition of mixed crystals. At early stages of polymerization, the process of initiation of the growth of polymer chains seems to be dependent on the concentration of defects associated with a misfit between pTS and pFBS molecules.     

Recognition of apoptotic cells by human peripheral blood monocytes does not alter their ability to phagocytize and kill Staphylococcus aureus

INTRODUCTION: During acute inflammation, leukocyte infiltration is mostly neutrophilic, but later monocytes prevail. The majority of inflammatory cells, particularly neutrophilic polymorphonuclear leukocytes (PMNs), become apoptotic at later stages of inflammation and are phagocytosed by neighboring cells, mostly by macrophages. Recently, it has been found that human peripheral blood monocytes also recognize apoptotic cells, which primes them to increased production of interleukin (IL)-10--a cytokine known to reduce phagocytes' ability to engulf and kill pathogens. Based on the above, we studied monocytes' ability to phagocytose and kill Staphylococcus aureus while in contact with apoptotic cells. MATERIALS AND METHODS: Monocytes isolated by elutriation were co-cultured with apoptotic PMNs or Jurkat cells and exposed to viable, human serum-opsonized S. aureus. To induce apoptosis PMNs were cultured overnight while Jurkat cells were UV-treated. Apoptosis, phagocytosis of bacteria and intracellular superoxide production were measured by flow cytometry. Production of reactive oxygen species was also followed by measurement of chemiluminescence. The bactericidal effect was determined by standard colony forming units method. RESULTS: Data presented show that contact of monocytes with apoptotic neutrophils and Jurkat cells had no influence on monocyte phagocytosis of S. aureus, the generation of reactive oxygen species, or the killing of bacteria. CONCLUSION: The data obtained suggest that monocytes attracted to the inflammatory site are not deficient in their ability to cope with pathogens after contact with apoptotic cells despite increased production of IL-10.     

Ionic liquids in embalming and tissue preservation. Can traditional formalin-fixation be replaced safely?

Ionic liquids (ILs) can be used for embalming and tissue preservation. ILs does not cause tissue damage and the tissue colour remains unaltered after treatment. Microscopical morphology of tissues fixed in ILs is of better quality than that of tissues fixed in formalin. Tissue preservation depends on the type of ILs. Best results were obtained with 1-methyl-3-octyloxymethylimidazolium tetrafluoroborate, the density of which resembles that of water. The salt is nonvaporous and when used as a formalin substitute, it eliminates health hazards in the pathological laboratory.     

Decrease of wheat flour allergenicity via lactic acid fermentation

Results of the research on the lowering of allergenicity of wheat flour fermented using homo- and heterofermentative lactic acid bacteria and mixed cultures with yeast were discussed. The gliadins’ immunoreactivity was measured using the indirect non-competitive enzyme-linked immunosorbent assay method. The biggest decrease of the immunoreactivity of gliadin fraction was observed in the case of fermentation performed with the use of mixed cultures of lactic acid bacteria and yeast. This way of wheat flour modification seems to be promising, because fermentation is a natural process causing not only lowering of the allergenicity, but also improving organoleptic and nutritional values of obtained products.     

Association between OPCRIT dimensions and polymorphisms of HPA axis genes in bipolar disorder

The aim of the study was to investigate the possible association between polymorphisms of HPA axis genes-CRHR₁ (corticotrophin-releasing hormone receptor), NR3C1 (glucocorticoid receptor) and AVPR1B (arginine vasopressin receptor) and dimensions of bipolar disorder assessed by OPCRIT.     

The Importance of Interleukin 18, Glutathione Peroxidase, and Selenium Concentration Changes in Acute Pancreatitis

Cytokinemia and oxidative stress are important factors responsible for an inadequate immune response in the early course of acute pancreatitis (AP). The aim of the study was to evaluate the profiles of interleukin 18 (IL-18), glutathione peroxidase (GPx), and selenium concentrations in serum with respect to AP severity and to study the relationships between these parameters and recognized prognostic indicators of AP severity. Prospective clinical analyses were performed on 61 patients with mild and severe forms of AP and for 15 healthy volunteers. In both forms of AP severity, the IL-18 concentration in the serum was significantly higher than in healthy controls. In the severe form of AP, the IL-18 concentration was the highest and exceeded significantly the values recorded on the 1st, 2nd, 3rd, 5th, and 10th days of mild AP. A significantly lower GPx concentration in the serum was recorded in severe AP compared to the mild form and in the control group. There was a significantly lower selenium concentration in the severe form of AP. Significant correlations between GPx and selenium, between IL-18 and GPx, and between IL-18 and selenium were recorded. The ROC analysis shows a high prognostic accuracy of IL-18 and GPx concentrations in the determination of AP severity. IL-18 is released early in the course of AP and may be a key immunomodulator of the inflammatory response in the severe form of this disease. Low GPx and selenium concentrations in severe AP reflect the lower antioxidative ability in this form of AP. IL-18 and GPx may represent new indicators of AP severity.     

The Effect of Increasing the Amount of Indium Alloying Material on the Efficiency of Sacrificial Aluminium Anodes

Al-Zn-In alloys having 4.2% zinc content and various indium content in the range of 0.02–0.2% were tested with respect to the most important electrochemical properties of sacrificial anodes in a cathodic protection, i.e., the current capacity and potential of the operating anode. The distribution of In and Zn in the tested alloys was mapped by means of the EDX technique, which demonstrated that these elements dissolve well in the alloy matrix and are evenly distributed within it. The current capacity of such alloys was determined by means of the method of determining the mass loss during the dissolution by a current of known charge. The results obtained demonstrate that the current capacity of Al-Zn-In alloy decreases with the increase in the In content, which results in an increased consumption of anode material and shorter lifetime of anodes. With 0.02% In content, the capacity amounted to approx. 2500 Ah/kg, whereas the alloy with 0.2% In had as much as 30% lower capacity amounting to approx. 1750 Ah/kg. Microscopic examination for the morphology and surface profile of the samples after their exposure demonstrated that a higher indium content in the alloy results in a more uneven general corrosion pattern during the dissolution of such alloy, and the cavities (pits) appearing on the alloy surface are larger and deeper. As the indium content is increased from 0.02% to 0.05%, the Al-Zn-In alloy potential decreases by about 50 mV to −1100 mV vs. Ag/AgCl electrode, which is advantageous in terms of using this alloy as a sacrificial anode. When the indium content is further increased from 0.05% to 0.2%, the potential of the alloy is no longer changed to a more negative one. The results obtained from all these tests demonstrate that alloys containing up to 0.05% of In additive are practically applicable for cathodic protection.