The effect of experimental removal of red foxesVulpes vulpes on spring density of brown haresLepus europaeus in western Poland

Red foxesVulpes vulpes (Linnaeus, 1758) were experimentally removed in two nearby areas located in western Poland to verify the hypothesis about the limiting impact of their predation on the low-density population of brown haresLepus europaeus (Pallas, 1778) (4.4-10.6 ind./km² in late autumn). In 1996/1997–2001/2002 foxes were culled (mainly in autumn and winter) in the reduction area (32 km²), whereas in the control area (34 km²) intensive culling was carried out only in 2000/2001–2001/2002. Indices of fox and hare spring densities were estimated using spotlight counts, as mean numbers of individuals observed per 10 km of the counting route. Annual changes in the fox density indices were negatively correlated with the bag of foxes, and annual changes in the hare density indices were negatively related to the annual changes in fox density indices. The fox density indices were significantly lower in the reduction area than in the control one only in 2000–2001 (2.8 times, on average), and in the same years, the hare population responded with higher density (1.7 times, on average). The hare responses took place without time delay, which suggests that the changes in fox abundance affected the situation of hares primarily in the autumn-winter season.     

Interleukin-1 receptor antagonist gene polymorphism affects the progression of chronic renal failure

End-stage renal disease (ESRD) involves an inflammatory process. Interleukin-1 receptor antagonist (IL-1Ra) and interleukin-1beta gene polymorphisms affect susceptibility to the disease in several inflammatory diseases. We investigated whether these polymorphisms are involved in ESRD by genotyping DNA from 602 dialyzed patients and 433 controls with polymerase chain reaction and digestion with restriction endonuclease. Allele 2 of the IL-1Ra VNTR polymorphism was associated with ESRD (OR=1.46, 95% CI 1.19-1.78). We also found a strong association between this allele and recurrent peritonitis in peritoneal dialysis patients. Odds ratio for the risk allele was higher compared to entire ESRD group (OR=3.6, 95% CI 1.70-7.44). The homozygosity for the allele 2 was associated with disease progression, especially in patients with diabetic nephropathy and glomerulonephritis. For the patients from these two subgroups having 2.2 genotype, the mean time from disease onset to ESRD was 1.5 and 2.2 years, respectively, compared to 6.4 and 9.8 years for those with 1.1 genotype. The IL-1Ra allele 2 is associated with ESRD in our dialyzed patients. Our results demonstrate for the first time the association of the IL-1Ra allele 2 with faster progression to ESRD. If confirmed in other populations, it might be a predictor of faster disease progression.     

Distribution, diversity and biomass of summer zooplankton from the coastal Canadian Beaufort Sea

Composition, abundance, biomass and distribution of zooplankton in the coastal Canadian Beaufort Sea were studied in the summer of 2005 and 2006. Data were collected from two cross-shelf transects (11 stations in each). Sampling was conducted with vertical hauls using a conical net of 153-μm mesh size. Our results revealed that there are three ecological zones, Intense Plume, Diffuse Plume and oceanic, which are primarily shaped by the highly variable Mackenzie River plume. The Intense Plume Grouping was located at stations influenced greatly by the Mackenzie River, where Podon leuckarti, Pseudocalanus spp., Copepoda nauplii and Limnocalanus macrurus were most abundant. The Diffuse Plume Grouping, that was located in the transitional zone between the river plume and the ocean, had the highest diversity. This grouping was characterised by high abundance of Copepoda nauplii, Polychaeta larvae, Pseudocalanus and L. macrurus. The Oceanic Grouping, located farthest from shore beyond the 85-m depth contour, was mainly inhabited by marine taxa—Calanus glacialis, C. hyperboreus, Triconia (Oncea) borealis and Microcalanus spp.—and had the greatest overall zooplankton abundance and biomass of all groupings.     

Segmental motions of rat thymidylate synthase leading to half‐the‐sites behavior

Thymidylate synthase (TS) is a homodimeric enzyme with two equivalent active sites composed of residues from both subunits. Despite the structural symmetry of the enzyme, certain experimental results are consistent with half‐the‐sites activity, suggesting negative cooperativity between the active sites. To gain insight into the mechanism behind this phenomenon, we explore segmental motions of rat TS in the absence of ligands, with normal mode analysis as a tool. Using solvent accessible surface area of the active site pocket as a monitor of the degree of opening of the active sites, we classified the first 25 nontrivial normal modes, obtained from the web server of the program ElNémo, according to the behavior of the active sites. We found seven modes that open and close both sites symmetrically and nine that do so in an anticorrelated fashion. We characterized the motions of these modes by visual inspection and through measurement of distances between selected atoms lining the active site pockets. The segments that regulate access to the active site correspond to the loop containing R44, helix K, and a long loop containing residues 103–125, in agreement with a large body of crystallographic studies. These elements can be activated together or in isolation. There are more asymmetric modes than symmetric ones in the set we analyzed, probably accounting for the half‐the‐sites behavior of the enzyme. Three of the asymmetric modes result in changes at the dimer interface and indicate the endpoints of possible communication pathways between the active sites. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 549–559, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

Image processing for accurate cell recognition and count on histologic slides

OBJECTIVE: To design an automatic system for recognition and count of two different cell families on histologic slides. STUDY DESIGN: The segmentation strategy uses color information on the image. The morphologic operations and Support Vector Machine approaches are used for each color to obtain precise segmentation of the image into separate cells for recognition. RESULTS: A large set of histologic slides of bone marrow was assessed byour system and the results compared to the score of a human expert. The results are in good agreement. The difference is within acceptable limits (below 10%). CONCLUSION: The automatic system of cell recognition and extraction is accurate and provides a useful tool for cell recognition and count on histologic slides.     

Binding of an oxindole alkaloid from Uncaria tomentosa to amyloid protein (Abeta1-40)

The primary aim of this work was to determine the interactions of an oxindole alkaloid (mitraphylline) isolated from Uncaria tomentosa with beta-amyloid 1-40 (Abeta1-40 protein) applying the capillary electrophoresis (CE) method. Specifically the Hummel-Dreyer method and Scatchard analysis were performed to study the binding of oxindole alkaloids with Abeta1-40 protein. Prior to these studies extraction of the alkaloid of interest was carried out. Identification of the isolated alkaloid was performed by the use of thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) combined with electrospray ionization mass spectrometry (ESI-MS). The proposed approach was proved to be an efficient and accurate method for specific compound isolation and identification purposes. Moreover, analytical information from the CE approach can be considered as the valuable tool for binding constant determination. The binding constant of mitraphylline with Abeta1-40 protein determined by the Hummel-Dreyer method and Scatchard analysis equals K = 9.95 x 10(5) M(-1). The results obtained showed the significant binding of the tested compound with Abeta1-40 protein. These results are discussed and interpreted in the view of developing a strategy for identification of novel compounds of great importance in Alzheimer disease therapy.     

Citropin 1.1-treated central venous catheters improve the efficacy of hydrophobic antibiotics in the treatment of experimental staphylococcal catheter-related infection

An in vitro antibiotic susceptibility assay for Staphylococcus aureus biofilms developed on 96-well polystyrene tissue culture plates was performed to elucidate the activity of citropin 1.1, rifampin and minocycline. Efficacy studies were performed in a rat model of staphylococcal CVC infection. Silastic catheters were implanted into the superior cava. Twenty-four hours after implantation the catheters were filled with citropin 1.1 (10 microg/mL). Thirty minutes later the rats were challenged via the CVC with 1.0 x 10(6) CFU of S. aureus strain Smith diffuse. Administration of antibiotics into the CVC (the antibiotic lock technique) began 24 h later. The study included: one control group (no CVC infection), one contaminated group that did not receive any antibiotic prophylaxis, one contaminated group that received citropin 1.1-treated CVC, two contaminated groups that received citropin 1.1-treated CVC plus rifampin and minocycline at concentrations equal to MBCs for adherent cells and 1024 microg/mL in a volume of 0.1 mL that filled the CVC and two contaminated groups that received rifampin or minocycline at the same concentrations. All catheters were explanted 7 days after implantation. Main outcome measures were: minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), synergy studies, quantitative culture of the biofilm formed on the catheters and surrounding venous tissues, and quantitative peripheral blood cultures. MICs of conventional antibiotics against the bacteria in a biofilm were at least four-fold higher than against the freely growing planktonic cells. In contrast, when antibiotics were used on citropin 1.1 pre-treated cells they showed comparable activity against both biofilm and planktonic organisms. The in vivo studies show that when CVCs were pre-treated with citropin 1.1 or with a high dose of antibiotics, biofilm bacterial load was reduced from 10(7) to 10(3) CFU/mL and bacteremia reduced from 10(3) to 10(1) CFU/mL. When CVCs were treated both with citropin 1.1 and antibiotics, biofilm bacterial load was further reduced to 10(1) CFU/mL and bacteremia was not detected, suggesting 100% elimination of bacteremia and a log 6 reduction in biofilm load. Citropin 1.1 significantly reduces bacterial load and enhances the effect of hydrophobic antibiotics in the treatment of CVC-associated S. aureus infections.     

Ritual behaviors associated with spermatophore transfer in Deuterosminthurus bicinctus (Collembola: Bourletiellidae)

The springtail Deuterosminthurus bicinctus, similarly to other members of Bourletiellidae, use their antennae, legs or heads to monopolize, stimulate, and direct female partners to spermatophores. The mating behavior of this species was examined by analysis of video recordings made on the leaves of its host plant. The characteristic stages of the behavioral sequence leading to sperm transfer were (1) preliminary courtship, highly variable in time and intensity—a male (rarely a female) endeavors to recruit a partner for further courtship, (2) push-and-retreat ritual—a rigid and rhythmical head-to-head dance of both partners, composed of some 180 phases and interspersed by several (3) free turns of a male and ended by (4) spermatophore deposition in front of a female, followed by stimulation of a female by a male to walk over the spermatophore, (5) spermatophore pick-up by a female with her gonopore, or alternately, (6) total spermatophore consumption by a female, as happened in 29% of the observed pairs. The mating ended always with (7) competition by both partners for the consumption of spermatophore residuals, usually won by the female. Comparison of mating elements and morphological features of partners engaged in mating sessions that ended either with spermatophore pick-up or consumption did not reveal any substantial differences. This suggests that changes in female motivation (hunger, state of impregnation) may be crucial for the male success in sperm transfer to a female. A digital video image is available at An erratum to this article can be found at     

Expression of SK3-type dehydrin in transporting organs is associated with cold acclimation in Solanum species

The expression of a gene, encoding a dehydrin protein designated as DHN24 was analyzed at the protein level in two groups of Solanum species differing in cold acclimation ability. The DHN24 protein displays consensus amino acid sequences of dehydrins, termed K- and S-segments. The S-segment precedes three K-segments, classifying the protein into SK₃-type dehydrins. A group of Solanum species able to cold acclimation constituted by S. sogarandinum and S. tuberosum, cv. Aster, and a second one composed of a S. sogarandinum line, that lost ability to cold acclimation, and of S. tuberosum, cv. Irga, displaying low ability to cold acclimation were studied. Under control conditions, noticeable levels of the DHN24 protein was observed in stems, tubers, and roots of Solanum species. No protein was detected in leaves. During low temperature treatment the DHN24 protein level substantially increased in tubers, in transporting organs and in apical parts, and only a small increase was observed in leaves. The increase in protein abundance was only observed in the plants able to cold acclimate and was found to parallel the acclimation capacity. Upon drought stress, the DHN24 level decreased in stems and in leaves, but increased in apical parts. These results suggest that Dhn24 expression is regulated by organ specific factors in the absence of stress and by factors related to cold acclimation processes during low temperature treatment in collaboration with organ-specific factors. A putative function of the SK₃-type dehydrin proteins during plant growth and in the tolerance to low temperature is discussed.