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Wielkopolski Park Narodowy jako atrakcyjny obszar do organizowania ścieżek dydaktycznych dla młodzieży szkolnej

100%

Szczepkowska A.

Badania Fizjograficzne nad Polską Zachodnią. Seria A: Geografia Fizyczna

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2004

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tom 55

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Sciezka przyrodnicza w Wielkopolskim Parku Narodowym: Jeziory - Lodz

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Szczepkowska A.

Morena

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2004

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tom 11

37-57

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Ekorozwój jako szansa rozwoju obszarów wiejskich

63%

Krukowski K., Szczepkowska A.

Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu

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1999

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tom 01

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nr 3

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Thyroid hormones in the cerebrospinal fluid of the third ventricle of adult female sheep during different periods of reproductive activity

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Skipor J., Misztal T., Szczepkowska A.

Polish Journal of Veterinary Sciences

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2010

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tom 13

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nr 4

Thyroid hormones (THs) are obligatory for transition from breeding season to anestrus in sheep. In this process, THs act during a very limited time of the year and primarily within the brain. In ewes chronically equipped for sampling cerebrospinal fluid (CSF) from the third ventricle, we have characterized the concentrations of total and free thyroxine (T4), triiodothyronine (T3), and total reverse T3 (rT3) in the CSF during breeding season, anestrus and during a critical period required for transition to anestrus (December-March). The total T4, T3, rT3 and free T3 average concentrations (± SEM) in CSF were 1.5 ± 0.07 ng/ml, 14.5 ± 1.2 pg/ml, 43 ± 7.4 pg/ml, and 0.6 ± 0.05 pg/ml, respectively, and all were significantly lower (p < 0.001) than in blood plasma except free T4 (12.6 ± 1.1 pg/ml), which was similar to that in plasma. There was a seasonal trend (p < 0.05) in the concentration of total T3 (highest in December) and free T4 (highest in November) in the CSF that does not follow that in blood plasma. During the period of transition to anestrus the CSF total T3/TT4 molar ratio and free T3/ T4 ratio were significantly lower (p < 0.05 and p < 0.01, respectively) than in blood plasma, while the total rT3/T4 ratio was significantly higher (p < 0.01) at the end of this period (March). Additionally, the CSF total rT3 concentrations were also significantly correlated with the CSF total T4 levels (r = 0.57; p < 0.05). In conclusion, the CSF in sheep may serve as a considerable source of thyroid hormones for neuroendocrine events. The lack of significant changes in THs concentrations in the CSF during the period of transition to anestrus indicate that neither seasonal changes of THs circulating in the blood plasma nor THs circulating in the CSF actively drive the transition to anestrus.

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Melatonin from slow-release implants upregulates claudin-2 in the ovine choroid plexus

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Szczepkowska A., Kowalewska M., Skipor J.

Journal of Physiology and Pharmacology

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2019

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tom 70

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nr 2

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Effect of a two-week treatment with low dose of ortho-substituted polychlorinated biphenyls (PCB104 and PCB153) on VEGF-receptor system expression in the choroid plexus in adult ewes

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Szczepkowska A., Mlynarczuk J., Grochowalski A., Dufourny L., Thiery J.-C., Skipor J.

Polish Journal of Veterinary Sciences

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2012

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tom 15

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nr 4

Ortho-substituted polychlorinated biphenyl (PCB) congeners, which constitute a large part of PCB residues found in the environment and in animal tissues, are known to exert potent vascular effects and can activate endothelial cells in the periphery and in the brain. The choroid plexus (CP) is responsible for cerebrospinal fluid (CSF) production and its epithelial cell layer is responsible for structure and functions of the blood-CSF barrier. The aims of this study were: 1) to investigate if environmentally relevant doses of PCB153 and similar doses of PCB104 caused changes in the expression of vascular endothelial growth factor (VEGF) - receptor system, which maintains CP function, and 2) to determine the level of both congeners in blood plasma after their oral administration. Studies of both congeners were performed on ovariectomized ewes treated per os with low doses (0.1 mg/kg, three times a week for two weeks) of PCB153 (n=4) or PCB104 (n=4) and vehicle (control, n=4). The effects of PCB153 and PCB104 treatment on mRNA expression of two isoforms of VEGF (VEGF120 and VEGF164) and their receptors Flt-1 and KDR were determined using real-time PCR. Plasma concentration of PCBs was measured using high resolution chromatography/tandem mass spectrometry (HRGC/MS-MS). We observed that neither PCB153 nor PCB104 significantly altered the mRNA of the VEGF-receptor system in the CP. In PCB treated animals plasma concentration of PCB153 (1.425 ± 0.16 ng/g of dry mass, DM) was about 150 times higher than PCB104 (0.009 ± 0.007ng/g DM). In control animals the PCB153 level was 0.14 ± 0.031 ng/g DM, while the PCB104 level was below detection level. This indicates that increase in plasma PCB153 concentration to levels similar to those reported in humans and of PCB104 concentration to levels 100 times higher than those found in human plasma did not affect the VEGF-receptor system in the CP in adult ewes. The significantly lower increase of PCB104 than PCB153 concentration in blood after oral administration suggests different absorption of both congeners from the digestive tract.

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Photoperiod alters the choroid plexus response to LPS-induced acute inflammation in ewes

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Skipor J., Szczepkowska A., Kowalewska M., Domzalska M., Herman A. P., Krawczynska A.

Annals of Animal Science

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2021

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tom 21

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nr 2

Ograniczanie wyników

2 Polish Journal of Veterinary Sciences

1 Annals of Animal Science

1 Badania Fizjograficzne nad Polską Zachodnią. Seria A: Geografia Fizyczna

1 Journal of Physiology and Pharmacology

1 Morena

1 Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu

7 Szczepkowska A.

4 Skipor J.

2 Kowalewska M.

1 Domzalska M.

1 Dufourny L.

1 Grochowalski A.

1 Herman A. P.

1 Krawczynska A.

1 Krukowski K.

1 Misztal T.

1 Mlynarczuk J.

1 Thiery J.-C.

1 2021

1 2019

1 2012

1 2010

2 2004