Multiple introductions determine the genetic structure of an invasive species population: American mink Neovison vison in Poland

Genetic diversity of feral and ranch American mink was studied in order to understand the processes of invasion and the possible influence of multiple introductions on the feral mink population in Poland. Tissue samples obtained from feral mink taken from 10 sites across Poland (196) and from ranch mink at nine mink farms (147) were genotyped at 14 microsatellite loci. Genetic differentiation among the separate regions and sites indicated some restriction in gene flow among them (pairwise F_ST values), and greater variation at microsatellite loci for feral mink was attributed to differences among sites rather than among regions (AMOVA). A Mantel test demonstrated a positive association of pairwise genetic and geographic distances. A total of five clusters of feral mink were identified and their spatial distribution partially reflected regional distribution, but also suggested that there were other factors (human-mediated propagule pressure) shaping mink genetic structure. Feral and ranch mink belong to two genetically separate clusters and an assignment test showed that 34 feral mink (17%) were assigned to the ranch mink clusters. The proportion of feral mink assigned to ranch mink clusters correlated with the size of the farm breeding stocks in the districts where sampling sites were located. High human-mediated propagule pressure (particularly in western Poland) increases feral population genetic diversity and overwhelms genetic structure and potential management units, making the control of mink populations less successful. Our results indicate that reducing number of escapees from farms should be required management action.     

The presence of androgen receptors in the epididymis and prostate of the stallion and cryptorchid horse--a preliminary study

Distribution of androgen receptors (ARs) in the epididymal duct and prostate of three entire stallions and one bilaterally cryptorchid horse was studied immunohistochemically using a polyclonal rabbit antiserum against the ARs. In both the healthy stallions and the cryptorchid, the epithelial cells of the epididymides showed nuclear staining for ARs. The intensity of AR-staining in the principal cells of the epididymis was stronger than that of the basal cells. In the prostate, the glandular secretory cells were moderately stained whereas the basal cells expressed weak AR-staining. Immunostaining for ARs in the reproductive tissues of the cryptorchid horse was always stronger than in those of the stallions. Our results demonstrate for the first time the AR localisation to equine epididymal and prostatic cells, which are directly regulated by androgens.     

The diagnosis of gastritis and helicobacter-like organisms infection in endoscopic biopsies of the canine gastric mucosa

The aim of this study was to evaluate the prevalence of gastric Helicobacter-like organisms (GHLO) and gastritis in the gastric mucosa of dogs with gastric disorders. Tissue samples of the gastric mucosa were obtained from 30 dogs with gastrointestinal symptoms (vomiting, abdominal pain or discomfort, loss of appetite) during endoscopy. Histopathological examinations were performed and occurrence of GHLO infection, gastritis and other mucosal changes were estimated. The GHLO infection and gastritis were identified in 63.3 and 36.6% of dogs respectively; other mucosal changes included fibrosis in the lamina propria, degenerative changes of the gastric glands and hyperplasia of the parietal cells. The present study has revealed that microscopically found gastritis is not frequent in dogs examined by endoscopy. GHLO infection can be responsible for some cases of gastritis and hyperplasia of parietal cells in dogs.     

Exposure to TNF-alpha but not IL-1beta impairs insulin-dependent phosphorylation of protein kinase B and p70S6k in mouse C2C12 myogenic cells

Tumor necrosis factor (TNF)-alpha is a proinflammatory cytokine considered to play an important role in muscle catabolism, but little is known about the mechanisms of its action. The aim of the present study was therefore to examine the effect of TNF-alpha pretreatment on glucose uptake and protein synthesis as well as the cellular content and phosphorylation of protein kinase B (PKB), p70S6k, Mitogen Activated Protein (MAP) kinase and p90rsk in mouse C2C12 myotubes stimulated with insulin. To determine whether interleukin (IL)-1beta might be involved in the catabolic action of TNF-alpha, the effects of IL-1beta were also tested. Experiments were performed on mouse C2C12 myoblasts subjected to differentiation in the presence of increasing concentrations of TNF-alpha (0.1-100 ng/ml) or IL-1 (5-50 ng/ml) for 5 or 6 days. Insulin (100 nmol/l) markedly stimulated glucose uptake in C2C12 myotubes (202.6% of control). This effect was profoundly attenuated by pretreatment with TNF-alpha at a concentration of 1 ng/ml (122.2% of control) and completely abolished by higher cytokine concentrations. Pretreatment of cells with TNF-alpha at a concentration of 1 ng/ml was also effective in diminishing the effect of insulin on protein synthesis, whereas higher cytokine concentrations prevented hormonal stimulation of protein synthesis in C2C12 myotubes. Pretreatment with TNF-alpha caused a significant decrease in PKB protein content. Insulin-mediated activation of protein kinase B was significantly diminished in cells differentiated in the presence of TNF-alpha. Treatment of C2C12 cells with insulin led to the gel mobility retardation of p70S6k indicating its phosphorylation and activation. In cells differentiated in the presence of TNF-alpha an approximately 2-fold decrease of insulin-mediated p70S6k phosphorylation was noted. Six-day differentiation of myogenic cells in the presence of TNF-alpha did not affect the protein content of p42MAPK, p44MAPK, p90rsk and phosphorylation of p42MAPK. Neither glucose uptake nor protein synthesis stimulated by insulin were affected significantly by pretreatment with IL-beta. Preincubation of myogenic cells with IL-1beta did not modify either the protein content of PKB and p70S6k or the insulin-stimulated phosphorylation of these kinases. In conclusion: i) high concentrations of TNF-alpha, but not IL-beta, present in the extracellular environment during myoblast differentiation prevent the stimulatory action of insulin on glucose uptake and protein synthesis; ii) insulin resistance induced by TNF-alpha in C2C12 myogenic cells could be associated with the decreased insulin-mediated phosphorylation of PKB and p70s6k, but not with the basal phosphorylation of p42MAPK.     

Dependence between acute phase response, oxidative status and mastitis of cows

There are many studies exploring the topic of acute phase response and oxidative status in inflammation of the mammary gland of cows. However, many phenomena are relatively not well known. Mastitis is associated with significantly higher concentrations of inflammatory and oxidative mediators in the cells and blood. Results of experiments have shown that there are evident changes in serum interleukins (IL), acidglycoprotein (alpha1AG), tumor necrosis factor (TNF), and haptoglobin (Hp). Thus, local as well as systemic inflammation might play important roles in increased mammary oxidative stress. Reactive oxygen species (ROS) have been implicated in the pathogenesis of a variety of diseases, including mastitis and in transgenic technology leading to production of new bacterial proteins, very important in prevention of mastitis. We can also observe an interaction between inflammatory and oxidative mediators. These results suggest an important role played by acute phase response and oxidative status in inflammation of the mammary gland.     

Real-time PCR analysis of p53 mRNA levels in tissues of whitefish (Coregonus lavaretus) exposed to benzo[a]pyrene

We developed a real-time PCR assay for measuring relative quantities (RQ) of p53 tumor suppressor mRNA in the whitefish (Coregonus lavaretus, Salmonidae, Teleostei). Real-time PCR primers for the p53 gene were designed from a region that was found to be conserved among salmonid p53 genes. To test for the usefulness of the assay we performed a treatment study, using benzo[a]pyrene (B[a]P) a putative p53-inducer. Two groups of hatchery raised whitefish, with an average body mass of 15 g and total length of 12 cm were either given an intraperitoneal injection (10 mg x kg(-1)) of B[a]P in corn oil (2 mg B[a]P ml(-1) corn oil) or corn oil alone (Control). After treatment (48 h, 7 degrees C), two random fish from each group were anesthetized and the liver, head kidney and brain were collected for mRNA isolation and analysis. In the control fish, relative quantification analysis based on the p53 mRNA levels in liver (RQ=1.00) showed higher basal levels of p53 mRNA in the head kidney (RQ= 1.69), and lower in the brain (RQ=0.41). In all three tissues sampled, p53 mRNA was affected by treatment with B[a]P. Liver tissue showed the greatest induction (RQ=1.53) from base levels (RQ=1.00), followed by brain (RQ=1.36), and head kidney (RQ=1.23). These results confirm that p53 mRNA is generally present at lower levels in differentiated tissues (liver and brain) than in those tissues with cell lines (head kidney), and demonstrate that p53 is moderately inducible by B[a]P in the whitefish. The approach presented here has the advantage of providing rapid and accurate measures of p53 induction in various tissues of fish responding to PAH contaminant exposure.     

Losses during Storage of Potato Varieties in Relation to Weather Conditions during the Vegetation Period and Temperatures during Long-Term Storage

Degradation of harvested tubers due to water loss, sprouting, and disease can cause severe economic difficulties in the cultivation of potatoes (Solanum tuberosum). This study evaluated the storage losses of new varieties of potato and determined the sprouting dates of potatoes stored at different temperatures. Additionally, this study evaluated the influence of weather conditions during the vegetative growth period on the date of sprouting in storage. After storage at three different temperatures (3, 5, and 8 °C), we estimated natural losses and losses caused by sprouting or the development of disease. The potato varieties stored at 3 °C, and 5 °C had similar weight losses (8.8% and 9.3%, respectively), but the potatoes stored at 8 °C had higher losses (10.8%). The average potato losses caused by disease ranged from 0.6% to 10%. The onset of sprouting of potatoes stored at 8 °C depended on the variety and began in the 20 day of December. Storage at 5 °C delayed sprouting by about 50 days compared with storage at 8 °C. Weather conditions (hot and rainy) during vegetative growth of the plants also influenced sprouting date, natural losses, and the amount of disease during storage. Our data showed a significant correlation between the hydrothermal coefficient during the vegetative period and the date of sprouting of potatoes during storage.     

Impact of fish size,water temperature,and MS‐222 concentration on inducing general anesthesia in pikeperch (Sander lucioperca)

The aim of the study was to determine the optimum concentration of MS‐222 for given size groups of pikeperch and water temperatures. The study considered three size groups of pikeperch (body weight [BW] 8.56, 15.72, 52.91 g), an MS‐222 water solution (50, 100, and 150 mg/L), and two temperatures (20 or 23°C). It was revealed that the optimum MS‐222 concentration depended largely on the size of the pikeperch and on water temperature. For fish with a BW <10 g the recommended concentration is 100 mg/L but only at 23°C. For fish with a BW of 10–40 g at an immersion temperature of 20°C the safe MS‐222 concentration ranges from 100 to 150 mg/L. However, at a temperature of 23°C the recommended concentration of the anesthetic is 100 mg/L. Similarly for larger fish, that is, fish with a BW >40 g, the optimum MS‐222 concentration at a water temperature of 20°C is in the range of 100–150 mg/L, but at a temperature of 23°C is it approximately 100 mg/L. Additionally, when exposure to the anesthetic is shorter (several min), a concentration of 150 mg/L is also safe for juvenile pikeperch of this size.     

Impact of inducing general anesthesia with Propiscin (etomidate) on the physiology and health of European perch (<Emphasis Type="Italic">Perca fluviatilis</Emphasis> L.)

The aim of the study was to describe the course and timing of the different stages of anesthesia induced with Propiscin (etomidate) on juvenile European perch (experiment I) and to describe the effect of immersing specimens of this species had on selected hematological and biochemical parameters (experiment II). The study was conducted on material with body weights (BW) of 162.98 (experiment I) and 171.60 g (experiment II). In experiment I, general anesthesia was induced with two different anesthetic concentrations (1 or 2 ml l^?1; anesthesia time 10 min). In experiment II, blood was drawn for hematological and biochemical analyses from the fish that had been exposed to anesthetic immersion baths with two different concentrations of Propiscin (1 and 2 ml l^?1) and for different exposure times (3 and 10 min). Blood samples were collected immediately following immersion (0 h) and 24 h later (24 h). Specimens that were immersed at the higher concentration of anesthetic achieved subsequent stages of general anesthesia two times faster (P ≤ 0.05). However, during recovery, some statistically significant differences were observed, but these lasted only until stage I was achieved. Among the hematological parameters (0 h), significant differences were observed in hematocrit (HCT) and mean corpuscular volume (MCV), while among the biochemical determinations (0 h), statistically significant differences were noted in the concentrations of glucose, calcium, lactate, and ammonia. After 24 h, the levels of these parameters in all fish groups returned to initial values. The hematological and biochemical tests conducted permit concluding that the anesthetic tested, at the concentrations (1 and 2 ml l^?1) and the exposure times of up to 10 min at which it was tested, is safe and can be used successfully to induce general anesthesia in perch.     

Viscoelastic Properties of Soil with Different Ammonium Nitrate Addition

Four different soils samples were taken from not cultivated recreational places. Particle-size distribution and pH (in water and in 1 M KCl) of the soil samples were measured. Soil samples were saturated with deionized water and solution of ammonium nitrate with the concentration of 5, 50 or 500 mM for 3 days. The samples were analyzed using dynamic oscillatory rheometer by frequency and strain sweeps. Soil samples were similar to physical gels, as they presented rheological properties between those of a concentrated biopolymer and a true gel. 50 mM concentration of the salt was enough to make changes in the elasticity of the soils. Small concentration of the fertilizer caused weakening of the soil samples structure. Higher concentration of ammonium nitrate caused the increase in the moduli crossover strain value. For the loam sample taken from a playground, with the highest content of the particles <0.002 mm (clay aluminosilicates), the lowest value of strain was observed at the moduli intersection. Lower strain value was necessary for the sliding shear effect of soil A sample effecting transgression to the “flowing” state. Strain sweep moduli crossover point can be used as a determinant of the rheological properties of soil.