Some aspects of purinergic signaling in the ventricular system of porcine brain

Background

Numerous signaling pathways function in the brain ventricular system, including the most important - GABAergic, glutaminergic and dopaminergic signaling. Purinergic signalization system - comprising nucleotide receptors, nucleotidases, ATP and adenosine and their degradation products - are also present in the brain. However, the precise role of nucleotide signalling pathway in the ventricular system has been not elucidated so far. The aim of our research was the identification of all three elements of purinergic signaling pathway in the porcine brain ventricular system.

Results

Besides nucleotide receptors on the ependymocytes surface, we studied purines and pyrimidines in the CSF, including mechanisms of nucleotide signaling in the swine model (Sus scrofa domestica). The results indicate presence of G proteins coupled P2Y receptors on ependymocytes and also P2X receptors engaged in fast signal transmission. Additionally we found in CSF nucleotides and adenosine in the concentration sufficient to P receptors activation. These extracellular nucleotides are metabolised by adenylate kinase and nucleotidases from at least two families: NTPDases and NPPases. A low activity of these nucleotide metabolising enzymes maintains nucleotides concentration in ventricular system in micromolar range. ATP is degraded into adenosine and inosine.

Conclusions

Our results confirm the thesis about cross-talking between brain and ventricular system functioning in physiological as well as pathological conditions. The close interaction of brain and ventricular system may elicit changes in qualitative and quantitative composition of purines and pyrimidines in CSF. These changes can be dependent on the physiological state of brain, including pathological processes in CNS.     

Influence of Catchment Characteristics and Flood Type on Relationship Between Streamwater Chemistry and Streamflow: Case Study from Carpathian Foothills in Poland

The study aimed to determine the influence of catchment characteristics and flood type on the relationship between streamflow and a number of chemical characteristics of streamwater. These were specific electrical conductivity (SC), pH, the concentrations of main ions (Ca²⁺, Mg²⁺, Na⁺, K⁺, HCO ₃ ^? , SO ₄ ^2? , and Cl^?), and nutrients (NH ₄ ⁺ , NO ₂ ^? , NO ₃ ^? , and PO ₄ ^3? ). These relationships were studied in three small catchments with different geological structure and land use. Several flood types were distinguished based on the factors that initiate flooding and specific conditions during events. Geological factors led to a lower SC and main ion concentrations at a given specific runoff in catchments built of resistant sandstone versus those built of less resistant sediments. A lower concentration of nutrients was detected in the semi-natural woodland catchment versus agricultural and mixed-use catchments, which are strongly impacted by human activity. The strongest correlation between streamflow and the chemical characteristics of water was found in the woodland catchment. Different types of floods were characterized by different ion concentrations. In the woodland catchment, higher SC and higher concentrations of most main ions were noted during storm-induced floods than during floods induced by prolonged rainfall. The opposite was true for the agricultural and mixed-use catchments. During snowmelt floods, SC, NO ₃ ^? , and most main ion concentrations were higher when the soil was unfrozen in the agricultural and mixed-use catchments versus when the soil was frozen. In the case of the remaining nutrients, lower concentrations of NH ₄ ⁺ were detected during rain-induced floods than during snowmelt floods. The opposite was true of PO ₄ ^3? .     

Exchangeable and Bioavailable Aluminium in the Mountain Forest Soil of Barania G��ra Range (Silesian Beskids, Poland)

The research was carried out in the spruce forests of Barania Góra (Silesian Beskids, Poland) affected by pandemic dying of trees. Twenty-seven samples were collected from the O layer in two plots: 17 in a cut down forest infested with insect pests (bark beetle) and ten in a 120-year-old healthy forest. The analyses covered basic parameters (pH(H2O), pH(KCl), w(org), C(tot), N(tot), CEC) and the concentrations of aluminium in the fractions leached with 0.1?M BaCl(2) (Al(exch)), 0.5?M CuCl(2) and 0.1?M Na(4)P(2)O(7) (Al(bio)) solutions. The total aluminium concentration in the soil was assayed digesting samples with hydrofluoric acid. The effect of pH and organic matter content on the amount of exchangeable (Al(exch)) and bioavailable (Al(exch)) aluminium in the soil was analysed. It has been found that the soils in both plots are strongly acidic and contain 550 to 1,700?mg?kg(-1) of exchangeable aluminium and 1,200 to 4,800?mg?kg(-1) of bioavailable aluminium. The lack of disease symptoms in the spruce trees in plot 2 can be explained by the higher content of organic matter in the soil. Unfortunately, one might expect that the high concentration of exchangeable aluminium will also cause the trees in the area to wither.     

Seeds in farmland food-webs: Resource importance,distribution and the impacts of farm management

Whilst considerable research effort in Europe has linked agricultural intensification with dramatic declines of seed-feeding birds, surprisingly little is known about the wider importance of seeds in animal food-webs. Moreover, understanding the dynamics of farmland seed food resources for species of conservation concern is of considerable research interest.We examined the distribution of berries and soil-surface seeds in the managed and unmanaged habitats of a 125 ha organic farm. We took soil suction-samples over a year, counted and identified all seeds, and compared abundances and species-richness between habitats. We constructed ecological networks from literature records and by rearing insects to investigate the importance of these seeds for insects, birds and mammals. We predicted the impacts of management on seed biomass, energy and the ecosystem service of pest control across the whole farm.We estimated seed and berry food resources of up to 33 metric tons of biomass and 560 GJ of energy on the farm. Potentially, more than 330 species use the seeds as a food resource, the overwhelming majority of which are invertebrates (82%) relying predominantly on non-crop and weed species. Generally, uncultivated semi-natural habitats such as woodland and mature hedgerows were more species-rich and had higher seed biomass and energy than crop habitats throughout the year, but fallow land was disproportionately important for seeds during the summer. Models of increased management intensity revealed declines of up to 19% in seed biomass and energy and cascades through the network that resulted in a substantial decrease in potentially pest-controlling parasitoids.     

Quantitative and qualitative comparison of three scoring systems for assessing recovery quality after general anaesthesia in horses

Objective To assess the reproducibility and repeatability of two commonly used recovery quality scoring systems and compare them with those of a novel system based on a greater number of objective criteria. Animals The video‐recorded recoveries of ten client‐owned horses selected from all recovery recordings taken between September 2005 and March 2006 at the Royal (Dick) School of Veterinary Studies. Materials and methods A digital versatile disc (DVD) was produced using edited video recordings of ten horses recovering from general anaesthesia. Twelve experienced equine anaesthetists (raters) studied the DVD on three occasions, and scored the recovery quality of each horse using one of three scoring systems (P, D or E) on each occasion. The process was repeated 6 months later (t = 6) to measure intra‐observer reliability (repeatability). At first use (t = 0) raters were asked to comment on the advantages and disadvantages of each system. Results Inter‐rater variability was limited for each system: at each observation period raters accounted for 0.3–4.4% variation. System P was insensitive to differences between recoveries. In system D, score variability increased as recovery quality deteriorated. Intra‐rater variability varied with system: using system P, raters provided consistent scores between the observation periods for some, but not all horses (‘horse’ and ‘rater’ accounted for 9.7% and 1.9% of variation respectively). Raters were less consistent between t = 0 and t = 6 using system D, but each horse was scored with similar consistency. System E produced little variation at the level of horse (1.0%) and rater (1.9%). Raters broadly agreed on the principle advantages and disadvantages of the three systems. Conclusions and clinical relevance The systems examined showed reliability and reproducibility but practicality and simplicity of use appeared to be inextricably linked with imprecision. Further work is required to produce a suitable recovery quality scoring system.     

Do psychological and physiological stressors alter the acute pain response to castration and tail docking in lambs?

Objective To investigate whether events that may be stressful to young lambs, including simulated infection or social isolation, modulate pain experienced by lambs following castration and tail docking (C/D). Study design Randomised, controlled, prospective study. Animals Fifty male lambs born to 46 second‐parity Mule ewes. Methods Lambs were allocated randomly to one of four groups, experiencing either a potential stressor or handling on day 2 after birth, followed by C/D or handling only on day 3. Quantitative sensory testing (QST) data [mechanical nociceptive thresholds (MNT), Semmes Weinstein filaments (SW), response to cold] and serum cortisol concentration were measured at time points after application of treatments to lambs on days 2 and 3 after birth. The treatment groups were LPS, injection of bacterial lipopolysaccharide IV on day 2, C/D on day 3; ISOL, isolation from the dam for 10 minutes on day 2, C/D on day 3; CAST, handling only on day 2, C/D on day 3; CONT, handled only on days 2 and 3. Results Castration and tail docking caused transient hypoalgesia as measured by MNT and SW. Simulated infection and isolation caused hyperalgesia 3 hours after application, indicated by a reduction in MNT, however they did not alter the pain response to C/D compared to lambs in the CAST group. Injection of LPS and C/D caused increased serum cortisol concentration. The magnitude of the cortisol response to C/D was not altered by prior exposure to either LPS or isolation. Conclusions and clinical relevance LPS and isolation did not modulate the response to C/D but did cause hyperalgesia. This highlights the importance of flock health management and husbandry techniques to reduce the incidence of either systemic infection or psychological stressors in young lambs.     

Biliothorax in a Siamese cat

A 2-year-old male neutered cat presented for further investigation of biliothorax. The cat was initially treated for pyothorax, including bilateral chest drains for lavage of the pleural space. Five days later, the pleural effusion turned clear-yellow and had a bilirubin concentration of 427 μmol/l compared to the serum bilirubin concentration of 15 μmol/l. Exploratory surgery revealed a 2mm tear in the diaphragm, with a corresponding 2mm defect in the diaphragmatic surface of the gall bladder, creating a fistula between the gall bladder and the pleural cavity. The defects were repaired routinely and the cat made a full recovery. It was suspected that the tears had been created at the time of the thoracostomy tube placement. Biliothorax has not been described before in a cat, and appears to be a rare complication following thoracostomy tube placement.     

Chemical pre-treatment of snapdragon spikes to increase cut-flower longevity

The longevity and quality of freshly cut snapdragon (Antirrhinum majus L.), as well as those kept under simulated transport, were enhanced by 20 h pre-treatment with a solution containing silver thiosulphate and sucrose, compared to those pre-treated with silver nitrate on sucrose alone. Solutions of silver nitrate, sucrose and EDTA or 8-HQC as a complexing agent were less effective in prolonging snapdragon vase-life. The results of experiments with radioactive silver showed that spikes treated with silver thiosulphate solution accumulated the greatest amount of silver, especially in the shoots.