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.     

Biodegradation of new quaternary ammonium compounds in treated wood by mould fungi

The degradation of seven potential wood preservatives based on imidazolium compounds (ICs) and quaternary ammonium compounds (QACs) with a modified anion structure by mould fungi was determined using soil-block method. Experiments were carried out on Scots pine (Pinus sylvestris L.) wood. Two-phase titration and high-performance liquid chromatography (HPLC) method were used to detect and quantify the degradation products. The performed soil-block tests showed that the ICs and QACs with alkoxymethyl substituents were leached from the experimental wood when in contact with moist soil and revealed their fungal detoxification by mould fungi, especially by Gliocladium roseum. The degree of biological decomposition of new compounds was higher than didecyldimethylammonium chloride and didecylmethylpoli(oxyethyl)ammonium propionate. The observations of the colonization by mould fungi were made using the scanning electron microscope (SEM). Decay of treated wood by mould fungi showed its tolerance to QACs.     

Phosphorus sources for winter oilseed rape (Brassica napus L.) during reproductive growth – magnesium sulfate management impact on P use efficiency

It has been assumed that phosphorus (P) resources accumulated in vegetative tissues of winter oilseed rape (WOSR) at flowering are too low to cover the requirements for the high-yielding crop during the seed filling period (SFP). The data used originated from field experiments with nutrients sequentially added to WOSR, using crops grown on soil rich in available P (2008–2010). The low-seed density canopies during SFP resulted only from the P remobilized from the pre-flowering crop resources. The high-seed density canopies depended on both P remobilized and its uptake from soil (PFPU). The maximum PFPU of 30.7 kg P ha^?1, and the concomitant seed density of 86.8 ? 10³ m^?2, resulted in a maximum seed yield of 5.8 t ha^?1. Internal P resources were reused during SFP irrespective of the initial P content and without impact on phosphorus use efficiency (PUE). The study showed that PUE improvement in WOSR is related to the seed density of primary branches. Its development depended on the supply of potassium, magnesium and sulfate. A PUE of 105.4 kg seed kg^?1 P was used to predict the seed yield gap (PYG). This index can be used as a measure of P management efficiency in WOSR canopy.     

Seroprevalence of Neospora caninum in dogs in south-western Poland

The prevalence of anti-Neospora caninum antibodies was determined in serum samples from 110 dogs in south-western Poland, using the indirect fluorescent antibody test (IFAT). Antibodies to N. caninum were found in 18 dogs (16.36%), of which 7 were also positive to Toxoplasma gondii. The titres of anti-N. caninum antibodies varied from 1:50 to 1:200.     

Morphological and functional alterations in adult boar epididymis: Effects of prenatal and postnatal administration of flutamide

Background

The dynamic cross-talk between epididymal cells is hormonally regulated and, in part, through direct cell-to-cell interactions. To date, no information is available regarding possible impact of anti-androgens on the proteins involved in the gap junctional communication within the boar epididymis. Thus, a question arised whether prenatal or postnatal exposure to an anti-androgen flutamide alters the expression of gap junction protein - connexin43 (Cx43) and androgen receptor (AR) expression in the caput, corpus and cauda epididymis and leads to delayed effects on morphology and function of adult pig epididymis.

Methods

First two experimental groups received flutamide prenatally on gestational days 20-28 and 80-88 (GD20 and GD80) and further two groups were exposed to flutamide postanatally on days 2-10 and 90-98 after birth (PD2 and PD90). Epididymides were collected from adult boars. Routine histology was performed using hematoxylin-eosin staining. The expression of Cx43 and AR were analyzed using immunohistochemistry and Western blotting. Both analyses were supported by quantitative approaches to demonstrate the variations of the expression levels following the treatment. Apoptotic cells were identified using TUNEL assay.

Results

Histological examination revealed differences in epididymal morphology of flutamide-exposed boars when compared to controls. Scarce spermatic content were seen within the corpus and cauda lumina of GD20, PD2 and PD90 groups. Concomitantly, frequency of epididymal cell apoptosis was significantly higher (p < 0.05) after exposure to flutamide at GD20. Moreover, in GD20, PD2, and PD90 groups, significantly lower AR expression (p < 0.05) was found in the principal and basal cells of the corpus and cauda regions, while in the stromal cells AR expression was significantly reduced (p < 0.05) along the epididymal duct. Concomitantly, a decrease in Cx43 expression (p < 0.05) was noticed in the stromal cells of the cauda region of GD20 and PD2 groups. This indicates high sensitivity of the stromal cells to androgen withdrawal.

Conclusions

The region-specific alterations in the epididymis morphology and scarce spermatic content within the lumina of the corpus and cauda indicate that flutamide can induce delayed effects on the epididymal function of the adult boar by decrease in AR protein levels that results in altered androgen signaling. This may cause disturbances in androgen-dependent processes including Cx43 (de)regulation, however, we can not exclude the possibility that in response to flutamide decreased Cx43 expression may represent one mechanism responsible for functional disturbance of the boar epididymis.     

Kinetics of the response of four positive acute phase proteins in pigs experimentally infected with toxigenic Pasteurella multocida

In the present study, acute phase proteins (APP) responses in pigs after infection with toxigenic strain of Pasteurella multocida (Pm) were evaluated. Twelve piglets from a herd free from toxigenic Pm were used. Six of them were infected intranasally with Pm. CRP, Hp, SAA and Pig-MAP concentrations were measured using commercial ELISA tests. CRP and Hp were significantly induced from 2 days post inoculation (dpi). The concentration of Hp in inoculated pigs remained elevated until the end of the study. The concentrations of SAA and Pig-MAP increased significantly from 3 dpi, and remained elevated to 5 or 7 dpi, respectively. Strong correlations were observed between concentration of Hp or SAA and changes in the lungs. No correlations were found between levels of APP in serum and changes observed in the turbinates. On the basis of our investigation, we cannot state that evaluation of APP concentrations in serum may provide useful information about severity of atrophic rhinitis. However, the concentration of all investigated APP increased after inoculation. Thus, APP-measurements may reveal ongoing infection. Monitoring of APP concentrations in the pig herds may help to pinpoint infected animals even before clinical signs are present. If found, these "APP-high" animals may be chosen next for pathogen-specific diagnostics. Early diagnosis and therapy may prevent the infection from spreading in the herd. Moreover, monitoring of APP concentrations in serum may be useful for selecting clinically healthy pigs before integration into an uninfected herd. Future studies should focus on the possibility of distinguishing infected and non-infected pigs under field conditions.     

Competitivity,selectivity, and heavy metals-induced alkaline cation displacement in soils

Abstract

The simultaneous incorporation of heavy metals into the soil is still a matter of great concern. Interaction (competitive sorption) between these metals and the soil solid phase may result in a deterioration of soil quality which relies basically on amounts of alkaline cations saturating soils sorptive complex. Results of this study indicate that Pb, Cu, C d, and Zn have induced solution pH decreases which were more intensive at highest metal loading rates. Partition parameters (Kd)-based sequences showed that Pb and Cu were more competitive than Cd and Zn and the overall selectivity sequence followed: Pb > Cu > Cd > Zn. Metal loadings and their competitive sorption have led to a strengthened displacement of alkaline cations (i.e. Ca²⁺, Mg²⁺, K⁺, Na⁺), especially of Ca²⁺ as a factor “stabilizing” soil sorptive complex. Such metals impact jointly with soils acidification are of great environmental concern since tremendous amounts of alkaline cations (especially Ca²⁺) may be potentially leached out, irrespective of the degree of soil contamination, as evidenced in the current study. High and positive ΔG values implied that the studied soils were characterized by generally low concentrations of exchangeable potassium which required high energy to get displaced (desorbed). Further studies on heavy metal uncontaminated or contaminated areas should be undertaken to provide with data which should be used for predictions on changes related to soil buffering capacity as impacted by heavy metal inputs.     

Influence of chronic caprine arthritis-encephalitis virus infection on the population of peripheral blood leukocytes

The influence of caprine arthritis-encephalitis (CAE) virus infection on the population of peripheral blood leukocytes in goats was evaluated. For this purpose two groups of adult dairy female goats were formed. The experimental group consisted of 17 goats, which had been naturally infected for many years. The control group comprised 29 non-infected goats, which originated from CAE-free herd. All goats were clinically healthy. Whole blood was collected and tested in hematological analyzer and light microscope to assess the total number of leukocytes and the percentage of four leukocyte populations--neutrophils, eosinophils, monocytes and lymphocytes. Then, flow cytometry with monoclonal antibodies against several surface antigens (namely CD14, CD2, B-B2, CD4, CD8h, TCR-N6, WC1-N2 and WC1-N3) was performed to assess the proportion of lymphocyte subpopulations. Statistically significant differences (alpha < or = 0.01) were observed only in the subpopulations of T lymphocytes--percentage of all subpopulations were significantly higher in the group of seropositive goats. No statistically significant differences were revealed with respect to the total number of blood leukocytes, the average percentage of blood leukocyte populations and proportions of both T and B lymphocytes.