Age-Dependent Effects of ELF-MF on Oxidative Stress in the Brain of Mongolian Gerbils

The aim of study was to investigate the effects of extremely low frequency magnetic field (ELF-MF; 50 Hz; 0.1, 0.25 and 0.5 mT) on oxidative stress in the brain of 3- (adult) and 10-month-old (middle-aged) gerbils. Nitric oxide (NO) level, superoxide (O₂ ^?) production, superoxide dismutase (SOD) activity, and index of lipid peroxidation (ILP) were measured in the forebrain cortex, striatum, hippocampus, and cerebellum immediately and 3 days after cessation of 7-day exposure. In all gerbils, ELF-MF significantly increased oxidative stress in all tested brain regions. This effect was correlated with the value of magnetic induction and was higher in middle-aged gerbils. Three days after cessation of exposure, the values of examined parameters were closer to control levels. In adult gerbils, the effect of ELF-MF of 0.1 mT on NO level, O₂ ^? production and SOD activity was almost fully disappeared, and ILP was at the control level regardless of the value of magnetic induction. In middle-aged gerbils, the effect of ELF-MF was still present but to a lesser degree than those observed immediately after cessation of exposure. These findings pointed out the ability of ELF-MF to induce age- and magnetic induction-dependent modification of oxidative stress in the brain.     

The first ferrocene analogues of muramyldipeptide

The two structurally interesting bioorganometallic analogues of muramyldipeptide (MDP) with potential immunomodulatory activity were synthesized starting from the O-protected N-acetylmuramic acid (MurNAc), l- or d-Ala and 1′-aminoferrocene-1-carboxylic acid (Fca). They were fully characterized by IR, ¹H NMR, ¹³C NMR and CD spectroscopy as well as by FD mass spectrometry.     

Tumor markers in breast cancer--evaluation of their clinical usefulness

Breast cancer is the most common neoplasm affecting women in the Western world. Many studies are still conducted with the purpose of finding markers that could be used for early diagnosis and/or serve as possible reliable prognostic or predictive parameters, but with conflicting results. At present, no markers are available for an early diagnosis of breast cancer For surveillance of patients with diagnosed breast cancer the most widely used serum markers are CA 15-3 and CEA which, in combination with other clinical parameters, could have clinical significance. The most useful and clinically important tissue-based markers in breast cancer are estrogen and progesterone receptors, used as a basis for hormonal therapy, and HER-2 receptors, essential in selecting patients for the treatment with Herceptin. New or potentially new markers for breast cancer include BRCA1 and BRCA2 genes for selecting patients at high risk of developing hereditary breast cancer, as well as urokinase plasminogen activator and inhibitor for assessing prognosis in lymph node-negative patients. Results of tumor and patient genetic analyses including their clinical evaluation will enable application of more individualized and personalized approach in diagnosis and therapy of breast cancer patients.     

Diurnal variation in airborne pollen concentrations of the selected taxa in Zagreb, Croatia

The number of individuals allergic to plant pollen has recently been on a constant increase. The knowledge of diurnal distribution and abundance of allergenic pollen types, their patterns and response to source position and weather is useful to correlate hay fever symptoms with the presence of allergenic pollen in the atmosphere. The aim of this study was to determine diurnal distribution of total airborne pollen, pollen of particular allergenic taxa, possible variation in diurnal pollen distribution at measuring sites placed at different heights, and effect of some meteorological parameters on airborne pollen concentrations. A 7-day Hirst-type volumetric pollen trap was used for pollen sampling. Qualitative and quantitative pollen analysis was performed under a light microscope (magnification x400). Total pollen of all plant taxa (Ambrosia sp., Betula sp., Cupressaceae, Urticaceae, Poaceae, Quercus sp., Fraxinus sp., Alnus sp., Corylus sp., Populus sp., Pinus sp., Picea sp.) observed showed a regular diurnal distribution at both sampling sites in both study years, with a rise in the pollen concentration recorded after 4.00 a.m. and 6.00 a.m., respectively. The peak pollen concentration occurred between 12.00 a.m. and 4.00 p.m., and the lowest diurnal pollen concentrations were recorded overnight. About 50% of the 24-h pollen concentration were released to the atmosphere between 10.00 a.m. and 4.00 p.m. The timing and size of diurnal peaks were closely related to high temperature, low humidity and south-west maximum wind direction.     

Growth modulation of human cells in vitro by mild oxidative stress and 1,4-dihydropyridine derivative antioxidants

Reactive oxygen species and lipid peroxidation products are not only cytotoxic but may also modulate signal transduction in cells. Accordingly, antioxidants may be considered as modifiers of cellular redox signaling. Therefore, the effects of two novel synthetic antioxidants, analogues of 1,4-dihydropyridine derivatives, cerebrocrast and Z41-74 were analysed in vitro on human osteosarcoma cell line HOS, the growth of which can be modulated by lipid peroxidation. The cells were pretreated with either cerebrocrast or Z41-74 and afterwards exposed to mild, copper induced lipid peroxidation or to 4-hydroxynonenal (HNE), the end product of lipid peroxidation. The results obtained have shown that both antioxidants exert growth modulating effects interfering with the lipid peroxidation. Namely, cells treated with antioxidants showed increased metabolic rate and cell growth, thereby attenuating the effects of lipid peroxidation. Such biomodulating effects of cerebrocrast and Z41-74 resembled growth modulating effects of HNE, suggesting that the antioxidants could eventually promote cellular adaptation to oxidative stress interacting with redox signaling and hydroxynonenal HNE-signal transduction pathways. This may be of particular relevance for better understanding the beneficial role of hydroxynonenal HNE in cell growth control. Therefore, cerebrocrast and Z41-74 could be convenient to study further oxidative homeostasis involving lipid peroxidation.     

Isolation,characterisation and phagocytic function of human macrophages from human peripheral blood

Molecular Biology Reports - Macrophages are among the most important cells of the immune system. Among other functions, they take part in almost all defense actions against foreign bodies and...     

Isolation and Characterization of vB_ArS-ArV2 – First Arthrobacter sp. Infecting Bacteriophage with Completely Sequenced Genome

This is the first report on a complete genome sequence and biological characterization of the phage that infects Arthrobacter. A novel virus vB_ArS-ArV2 (ArV2) was isolated from soil using Arthrobacter sp. 68b strain for phage propagation. Based on transmission electron microscopy, ArV2 belongs to the family Siphoviridae and has an isometric head (∼63 nm in diameter) with a non-contractile flexible tail (∼194×10 nm) and six short tail fibers. ArV2 possesses a linear, double-stranded DNA genome (37,372 bp) with a G+C content of 62.73%. The genome contains 68 ORFs yet encodes no tRNA genes. A total of 28 ArV2 ORFs have no known functions and lack any reliable database matches. Proteomic analysis led to the experimental identification of 14 virion proteins, including 9 that were predicted by bioinformatics approaches. Comparative phylogenetic analysis, based on the amino acid sequence alignment of conserved proteins, set ArV2 apart from other siphoviruses. The data presented here will help to advance our understanding of Arthrobacter phage population and will extend our knowledge about the interaction between this particular host and its phages.     

Intraspecies variability in Vipera ammodytes ammodytes venom related to its toxicity and immunogenic potential

Vipera ammodytes is the most venomous European snake, whose venom has been used as antigen for immunization of antivenom-producing animals. Same as venom of any other snake, it is a complex mixture of proteins, peptides and other compounds which biochemical and pharmacological variability has been demonstrated at interspecies and intraspecies level. In this work we demonstrated intraspecific variability between 8 venom production batches using both the conventional and the new methodology. Moreover, in contrast to the literature on different venoms' variability, for the first time we were able to select those biochemical differences that are related to and give information on the venom's toxicity and immunogenicity. We have shown that methods quantifying ammodytoxin (the most toxic compound identified so far in the Vipera ammodytes ammodytes venom) content of the venom clearly distinguish between high and low immunogenic venoms.