No abstract

No abstract

Qualitative and quantitative mass spectrometric studies of biomolecules for example proteins, peptides, or lipids contained in biological samples like physiologic fluids are very important for many fields of science such as medicine, veterinary medicine, biology, biochemistry, molecular biology, or environmental sciences. In the last two decades, MALDI TOF MS — matrix-assisted laser desorption mass spectrometry, proved to be an especially convenient tool for these analyses. The main advantages of this method are its rapidity and high sensitivity which is particularly appreciated in the case of studies of complex biological specimen. A major challenge for many researchers is to maximize this sensitivity, among others, by appropriate procedures of sample preparation for the measurement. The objective of this work was to optimize these procedures, selecting the optimal matrix and optimum proportions of the sample and the matrix solution in a mixture of both solutions, aiming at the achievement of the maximum intensity of ion current. In this respect, five low molecular mass cathelicidins were studied: prophenin-2, protegrins 1–3, PR-39. All of them were obtained directly from the porcine blood. As a result of studies, the authors determined such experimental conditions when the intensity of investigated ionic current had the highest value.

The platelet-rich plasma (PRP) and antimicrobial peptides neutrophil extract (AMP extract) were prepared from rabbit neutrophils as two autologous blood-derived preparations, which could be applied locally to enhance healing process of tissues. Both preparations were analyzed using the MALDI TOF method for accurate qualitative assay. Growth factors (PDGF and VEGF) and microbicidal protein were reported in PRP. In AMP extract a-defensins, namely; NP-1, -2, -3a, -3b, -4, and -5 and cathelicidins represented among other by 15-kDa antibacterial protein (p15s) were detected. In the second part of our study the influence of antimicrobial extract on macrophages in vitro was tested. Then, degranulation of neutrophils in vitro and generation of reactive intermediates by these cells under the influence of AMP extract were assessed. As estimated, the addition of AMP extract into cultures of macrophages decreased superoxide anion generation after 5 days of incubation. Furthermore, AMP extract inhibited degranulation and respiratory burst in neutrophils, therefore in this regard it suppress proinflammatory effect of two studied populations of leukocytes.

We report the results of experimental studies on the effects of sample supports in laser desorption/ionization mass spectrometry (LDI-MS). LDI time-of-flight (TOF) mass spectra obtained for C(60) and insulin samples deposited onto standard stainless steel substrate and/or onto some non-metallic materials (glass, scotch tape, floppy disc foil, Teflon foil, photocopy film), all recorded under identical, typical experimental conditions, have been compared with regard to their intensity and quality. The LDI investigations show that compared with stainless steel, glass and floppy disc foil sample supports boost (2-3.5 times) ion yields for C(60)(+) and C(60)(-) ions, respectively. The stainless steel and scotch tape sample supports are the best for the mass resolution of positive ions and the formation of (C(60))(n)(-) (n

No abstract

We report results of experimental studies on the silver clusters formation in laser desorption and matrix assisted laser desorption. Time-of-flight mass spectrometer was used to control process itself. Firstly, we investigated dependence of silver salts of variety chemical nature on formation of silver clusters. The most prominent was usage of organic silver salts (silver trifluoroacetate and silver benzoate). The biggest species obtained was Ag + 45(silver benzoate). Secondly, we examined influence of organic matrix (2,5-dihydroxybenzoic acid) on formation efficiency of silver clusters in matrix assisted laser desorption. In all cases we observed increase of silver clusters size.

Antimicrobial peptides are important elements of host defence because of their direct antimicrobial activity and modulatory role in innate immune response. The purpose of the study was to determine whether porcine peptides PR-39, protegrins (PGs) and low molecular weight extract (LMWE) are able to influence the neutrophil response during bone graft implantation in rabbits. The study was conducted on 10 White New Zealand rabbits and neutrophil activity was assayed on the basis of elastase, myeloperoxidase, and alkaline phosphatase release as well as free radical generation. Our study showed that PR-39 and PGs inhibited enzyme release from neutrophils except for elastase, which is essential in the first phase of injury. Superoxide and nitric oxide generation under the influence of PR-39 and PGs were also decreased. Moreover, we found that unlike separated peptides PR-39 and PGs, LMWE acts proinflammatorily, intensifying the neutrophil secretory response and free radical generation. These results should be taken into account in treatment with natural antimicrobial peptides. The increased neutrophil responses in the first phase of inflammation during surgery may be useful in prevention of infection, but LMWE should not be used in conditions in which excessive neutrophil response is injurious.