Impaired leptin activity in New Zealand Obese mice: model of angiogenesis

Leptin is prompt to drive angiogenesis, effecting proper vascularisation. Tissue remodeling (including adipose organ) is associated with the angiogenic response. The aim of this study was to investigate the effect of hyperleptinemia on angiogenesis in subcutaneous (s.c.) in vivo matrigel model in mice on a high fat (HF) diet. HF promoted adipose tissue accumulation and biochemical changes resembling metabolic syndrome. However, the impact of this dietary treatment on angiogenesis, measured in s.c. matrigel model was not significant. Changes in leptin concentration were not accompanied by significant angiogenic response. This lack of leptin activity and impaired signal transduction at the molecular level suggests malfunction of the leptin receptor in NZO mice.     

The role of chemical information in shaping the spatial activity of bank voles in a free-living population

A field experiment was carried out in two types of forest environment — a relatively homogenous mixed coniferous forest with low plant species diversity and a reach and spatially differentiated alder wood. Spatial variation in activity of voles was sampled by placing ink pads and paper inside PVC waterpipes laid in a line on the forest floor. In the first stage of the experiment, use of space by bank volesClethrionomys glareolus (Schreber, 1780) was analysed without any bait in track collection tubes. In the second stage, we used an attractant in the form of scent collected from alien bank vole individuals of different sex (males, females), age (juveniles, adults) and physiological state (sexually active and not active). In the coniferous forest the distribution of number of visits in tracking tubes was of aggregated character both before and after providing odour of alien individuals. In the alder wood the aggregation level that had been initially lower than in the coniferous forest increased after providing scent. As a consequence, placing scent of alien individuals resulted in decreasing differences in animal distribution in both habitats. The results allow also to the supposition that the reaction to scent depends on sex, age, and the physiological state of the donor.     

Synthesis and spectroscopy of diethyl (pyridinylmethyl)phosphates and their palladium (II) complexes: X-ray crystal structures of Pd(II) complexes

The synthesis of diethyl (pyridin-2-, -3-, -4-ylmethyl)phosphate (2-pmOpe, 3-pmOpe, 4-pmOpe) ligands and their palladium (II) complexes of general formula trans-[PdCl₂L₂] (L = 2-pmOpe, 3-pmOpe,4-pmOpe) has been described. Pyridine phosphate derivatives were synthesized via the condensation of phosphorochloridic acid diethyl ester with an appropriate pyridinylmethanol in the presence of triethylamine. The compounds have been identified and characterized by IR, far-IR, ¹H NMR, ³¹P NMR, ³¹P CP-MAS NMR and elemental analyses. The crystal and molecular structures of palladium (II) complexes, i.e., [PdCl₂(2-pmOpe)₂] and [PdCl₂(4-pmOpe)₂] determined by the X-ray diffraction method, are presented. In both structures, Pd(II) ions are four-coordinated by two chlorine atoms and two pyridine nitrogen atoms. The geometry of complexes is square-planar and adopt a trans configuration, which is consistent with preparation method.     

Heavy metals in the brain of long-tailed duck (Clangula hyemalis) wintering in the Pomeranian Bay,Poland

Males (n=34) and females (n=23) of long-tailed duck (Clangula hyemalis) collected on the southern coast of the Baltic Sea in winter were studied to determine brain tissue concentration of iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), and cadmium (Cd). There were no significant differences in the concentration of metals between males and females, except for Cd, the concentration of which in male brains was twice that of the females. In the brains of 20 birds (41% male and 26% female), the lead (Pb) concentration exceeded 1 μg/g wet wt. In all the duck brains examined, Spearman correlation coefficients were significant and positive for Zn−Mn, Cu−Mn, Cu−Fe, and Pb−Fe; a negative correlation was found for Pb−Zn. Additionally, female brains showed a positive correlation between Pb and Fe. The results obtained were compared with literature data for diving and nondiving anseriforms and birds of other taxa. It seems that concentration of heavy metals in the brain tissue of birds reflect natural adaptations (e.g., for diving) as well as effects of environmental pollution.