Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 20

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Prawo chroniące środowisko w obszarze rolnictwa

100%
Malecki A.
Zeszyty Naukowe Uniwersytetu Zielonogórskiego. Inżynieria Środowiska
|
2004
|
nr 12[131]
2

Jakość wód podziemnych zlewni bezpośredniej Jeziora Sławskiego

100%
Malecki A.
Zeszyty Naukowe Uniwersytetu Zielonogórskiego. Inżynieria Środowiska
|
2007
|
nr 13[133]
3

Zrównoważony rozwój rolnictwa zintegrowanego

100%
Malecki A.
Zeszyty Naukowe Uniwersytetu Zielonogórskiego. Inżynieria Środowiska
|
2004
|
nr 12[131]
4

Bilans azotu i fosforu w zlewniach cząstkowych Jeziora Sławskiego

100%
Malecki A.
Zeszyty Naukowe Uniwersytetu Zielonogórskiego. Inżynieria Środowiska
|
2007
|
nr 13[133]
5

Zasoby pracy w zlewni Obrzycy

100%
Malecki A.
Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu
|
2004
|
tom 06
|
nr 3
6

Śmiertelność szczeniąt lisów polarnych

63%
Narucka I., Malecki A.
Roczniki Akademii Rolniczej w Poznaniu. Zootechnika
|
1984
|
tom 31
7

Fluorometric assay of oleate-activated phospholipase D isoenzyme in membranes of rat nervous tissue and human platelets

51%
Krzystanek M., Trzeciak H. I., Krzystanek E., Malecki A.
Acta Biochimica Polonica
|
2010
|
tom 57
|
nr 3
 Phospholipase D plays a key role in the biosynthesis of phosphatidic acid, a second messenger involved in essential cellular processes. Oleate-activated phospholipase D was the first mammalian phospholipase D isoform to be discovered but is the least known. The study was aimed to test a fluorometric method of assessment of oleate-activated phospholipase D activity in different biological materials. The brain cortex of male Wistar rats, cultured rat brain astrocytes, and human platelets were processed to yield plasmatic membranes for experiments. To assess phospholipase D activity the modified fluorometric method was used. Previously, the method was used only to determine H2O2. In this enzyme-coupled assay phospholipase D activity is monitored indirectly using 10-acetyl-3,7-dihydroxyphenoxazine. First, phospholipase D cleaves exogenous phosphatidylcholine to yield choline and phosphatidic acid. Second, choline is oxidized by choline oxidase to betaine and H2O2. Finally, in the presence of horseradish peroxidase, H2O2 reacts with 10-acetyl-3,7-dihydroxyphenoxazine to generate the highly fluorescent product, resorufin. The concentration of resorufin was measured using excitation and emission at 560 nm and 590 nm, respectively. The proposed optimal parameters of the tested assay are 25 μg of rat brain cortex protein, 50 μg of rat brain astrocyte protein, and 50 μg of human platelet protein in a reaction volume of 200 μL, and 2 min enzymatic reaction at 37°C. The fluorometric method may be applied to assay phospholipase D in different biological materials.
8

Modulation of arachidonic acid incorporation into cultured spinal cord neurons

51%
Malecki A., Chalimoniuk M., Trzeciak H. I., Toborek M.
Acta Neurobiologiae Experimentalis
|
2001
|
tom 61
|
nr 3
9

Human gyrovirus-apoptin interferes with the cell cycle and induces G2/M arrest prior to apoptosis

51%
Chaabane W., Ghavami S., Malecki A., Los M. J.
Archivum Immunologiae et Therapiae Experimentalis
|
2017
|
tom 65
|
nr 6
10

Effect of heavy metals in coal dust on the morphological structure and cellular enzymatic markers of rat lungs

51%
Trzeciak H. I., Kaminski M., Malecki A., Pudelko A.
Acta Poloniae Toxicologica
|
1995
|
tom 03
|
nr 1
11

The effect of glutamic acid, N-acetylcysteine, ebselen in oxygen-glucose deprivation conditions on signaling kinases and structural and functional proteins of rat brain endothelial cells in vitro

45%
Bernacki J.1, Nierwinska K.2, Pudelko A.1, Dobrowolska A.1, Malecki A.1,2 J., Nierwinska K., Pudelko A., Dobrowolska A., Malecki A.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr 1
The expression of signaling kinases and specific junctional proteins (VE-cadherin, occludin, claudin, JAM-1) and transport proteins (MDR-1) were measured in rat’s brain endothelial cells cultured in vitro and exposed to simulated ischaemic conditions (OGD, oxygen-glucose deprivation). The effects of ebselen, Nacetylcysteine and glutamic acid were evaluated either in normoxic or simulated ischaemic conditions. Endothelial cells isolated from the fragments of rat brain microvessels seeded on the cell culture plates were cultured at 370 C in Dulbecco’s modified Eagle’s medium containing 20% fetal bovine serum, antibiotics and bFGF. OGD was obtained by incubation of cells in humidified atmosphere (3%O2, 92% N2, 5% CO2) in culture medium deprived of glucose and serum. Confluent cultures of endothelial cells were exposed to: 5000µM glutamic acid, 200µM N-acetylcysteine or 20µM ebselen. Intracellular signaling kinases (Akt, ERK1/2) and junctional and transporter proteins (VE-cadherin, occludin, claudin, JAM-1 and MDR-1) were detected using Western-blot. Ischemic conditions exerted negative effects on tight junctions of brain endothelial cells. ERK kinases were involved in the transduction of signals induced by ischemic conditions or by glutamic acid. Glutamic acid receptors were involved either in activation or inhibition of this pathway. In simulated ischaemic conditions ebselen as well as ebselen in combination with N-acetylocysteine exerted negative effects on intercellular junctions between brain endothelial cells. Antiooxidant compounds: N-acetylocysteine and ebselen affected MDR-1 level in brain endothelial cells. Supported by MNiSW grant 2P05A01530.
12

The effect of blood lead concentration on EEG, brain electrical activity mapping and psychological test results in children

45%
Kmiecik-Malecka E., Malecki A., Pawlas N., Wozniakova Y., Pawlas K.
Polish Journal of Environmental Studies
|
2009
|
tom 18
|
nr 6
Our study focused on the assessment of the effects of environmental lead exposure on brain electrical activity. Electrophysiological procedures were conducted on 92 children with Pb level of 5.9 + 3.8 μg/dL (min.=2.3 μg/dL, max.=23.0 μg/dL). The study was performed on a blind basis, and consisted of blood lead level measurements, standard EEG examinations, brain electric activity mapping, and psychological tests. Results of electrophysiological assessment were correlated with the blood lead concentration (PbB). Elevated PbB significantly correlated with: abnormal EEGs (R=0.419; p<0.001), border-line results, IQ measurement results and difficulties in learning. In conclusion, psychological tests and electrophysiological methods were effective in the assessment of environmental exposure of children to lead.
13

Involvement of multiple protein kinases in cPLA2 phosphorylation, AA release and cell death in astrocyte treated with 1-methyl-4-phenylpyridinium-the possible key role of PKG

45%
Chalimoniuk M., Stolecka A., Gabryel B., Malecki A., Langfort J.
Acta Neurobiologiae Experimentalis
|
2009
|
tom 69
|
nr 1
Cytosolic phospholipase A2 (cPLA2) demonstrates selective affi nity to arachidonic acid (AA) liberation, which is known to be elevated in PD. We indicated that NO/GC/cGMP pathway was upregulated in the primary astrocyte culture treated with MPP+. We investigated if the cGMP/cGMP-dependent protein kinase (PKG) signaling pathway was involved in 1-methyl-4-phenylpyridinium (MPP+)-induced cPLA2 activation of the primary astrocyte culture. We found increased levels of total and phosphorylated cPLA2 and increased AA release in the primary astrocyte culture exposed to MPP+. We used cPLA2-specifi c inhibitors and Ca2+- independent PLA2 (iPLA2), and we found that cPLA2 released more AA after stimulation with MPP+ than iPLA2 and that there was a time-dependent delay of AA release by iPLA2 compared to cPLA2. The PKG inhibitor KT5823 decreased MPP-induced AA release in the primary astrocyte culture. KT5823, in addition to PKC and ERK1/2 inhibitors, decreased cPLA2 activity as well as total and phosphorylated cPLA2 protein levels in the astrocyte treated with MPP+. Dual treatment with PKG and PKC or ERK1/2 inhibitors had the same effect on cPLA2 activity and protein levels. PKG is involved in the enhancement of cPLA2 phosphorylation at Serine-505 and in AA release in the astrocyte exposed to MPP+. Our results indicate that the nNOS/cGMP/ PKG pathway stimulates cPLA2 phosphorylation at Ser-505 by activation of PKC or ERK1/2. These results suggest that activation of cPLA2 by upregulation nNOS/cGMP pathway may play important role in MPP+-induced astrocyte activation, neurotoxicity and oxidative stress in the nigrostriatal system.
14

Effect of coal dusts containing heavy metals on structure, cellular enzymatic markers, and cytochrome P-450-dependent monooxygenase system in rat kidney

45%
Trzeciak H. I., Kaminski M., Plewka A., Malecki A., Pudelko A.
Polish Journal of Environmental Studies
|
1996
|
tom 05
|
nr 2
We evaluated morphological changes, the activities of succinate dehydrogenase, lactate dehydrogenase, glucose-6-phosphatase, Mg2+ -dependent adenosine triphosphatase, and acid phosphatase, and the activity of the cytochrome P-450-dependent monooxygenase system in the kidneys of rats exposed to coal dusts containing either very low or high amounts of heavy metals. We showed that the coal dust with a very low content of heavy metals (VLCHM) did not produce any structural lesions, but increased significantly the activities of the enzymes. These changes probably reflected kidney adaptation to the unfavorable conditions caused by the metals. The interactions among them reduced the eventual nephrotoxic effect of their action. The coal dust with a high content of heavy metals (HCHM) damaged proximal convoluted tubules, straight tubules, and, to a lesser degree, distal convoluted tubules, especially those of long-looped nephrones. The levels and the activities of the assayed cytochromes decreased significantly in the kidneys of rats exposed to HCHM coal dust.
15

Effect of coal dusts containing heavy metals on the structure, cellular enzymatic markers, and cytochrome P-450-dependent monooxygenase system in rat kidneys

45%
Trzeciak H. I., Kaminski M., Plewka A., Malecki A., Pudelko A.
Polish Journal of Environmental Studies
|
1995
|
tom 04
|
nr 4
We evaluated morphological changes, the activities of succinate dehydrogenase, lactate dehydrogenase, glucoso-6-phosphatase, Mg2+-dependent adenosine triphosphatase, and acid phosphatase, and the activity of the cytochrome P-450-dependent monooxygenase system in rat kidneys exposed to coal dusts containing either low or high amounts of heavy metals. We showed that the coal dust with a very low content of heavy metals (VLCHM) did not produce any structural lesions, but significantly increased the activities of the enzymes. These changes probably reflected kidney adaptation to unfavorable conditions caused by the metals. The interactions among them reduced the eventual nephrotoxic effect of their action. The coal dust with high content of heavy metals (HCHM) damaged proximal convoluted tubules, straight tubules, and, to a lesser degree, distal convoluted tubules, especially those of long-looped nephrones. The levels and the activities of the assayed cytochromes decreased significantly in the kidneys of rats exposed to HCHM coal dust.
16

Effects of coal dusts with different concentrations of metals on structure, hepatocellular enzymatic markers, and cytochrome P-450-dependent monooxygenase system in rat liver

45%
Trzeciak H. I., Kaminski M., Plewka A., Malecki A., Gabryel B.
Polish Journal of Environmental Studies
|
1996
|
tom 05
|
nr 1
For three months rat livers absorbed coal dust containing low or high concentrations of heavy metals. We found that these concentrations of heavy metals significantly decrease cytochrome P-450 content in hepatic microsomes, and that this decrease correlates with the concentration of heavy metals. Furthermore, we have shown that only coal dust with high heavy metal content produces such structural lesions as necrosis and apoptosis in zone III of the acinus. These lesions are accompanied by increased intracellular catabolism (acid phosphatase), and by considerably decreased activities of enzymes, which are markers of energy production (succinate and lactate dehydrogenase), glycogen metabolism (gluco- se-6-phosphatase), and active excretion of metabolites into bile (adenosine triphosphatase stimulated by Mg++).
17

Ketogenic diets based on fat of either animal or plant origin have different effects on the abundance of autophagic vesicles in mouse brain

33%
Liskiewicz D., Liskiewicz A., Nowacka-Chmielewska M., Jablonska K., Grabowski M., Student S., Slugocka A., Przybyla M., Barski J. J., Malecki A.
Acta Neurobiologiae Experimentalis
|
2019
|
tom 79
|
nr Suppl.1
INTRODUCTION: Autophagy is a cellular recycling mechanism essential for maintenance of cell homeostasis and viability, especially during stress conditions; hence, autophagy is involved in a number of physiological and pathological processes. Autophagy is thought to be involved in anti‑aging and neuroprotective effects of caloric restriction, Sirtuin 1 activation, inhibition of insulin/ insulin-like growth factor signaling, and administration of rapamycin, resveratrol, and metformin. The ketogenic diet mimics the biochemical actions of fasting and exerts many physiological and cellular responses similar to those evoked by intermittent energy restriction. Despite this, the relationship between nutritional ketosis and autophagy has been a largely unexplored field. AIM(S): The aim of this study was to verify the hypothesis that ketogenic diets affect the process of autophagosome formation in the hippocampus and/or cerebral cortex. METHOD(S): 9-week-old male mice were fed with one of two differently composed ketogenic chows – based on the fat of either animal or plant origin (KA, KP respectively) or with standard rodent chow (SD) – for 6 subsequent weeks. Western blotting, (LC3, p62), QRT‑PCR (LC3A, LC3B, p62), and confocal microscopy (LC3 puncta) were employed to monitor autophagy in hippocampal and cerebrocortical samples. RESULTS: Western blot results revealed increased levels of LC3 II protein – a marker of autophagosomes – in the hippocampus and frontal cortex of mice treated with the ketogenic diet. This observation was confirmed by the evaluation of a number of LC3 puncta with immunofluorescence microscopy. The size of this effect was dependent on the composition of the diet. CONCLUSIONS: This study reports, for the first time, an upregulation of autophagosome synthesis in the brain of animals fed with the ketogenic diet. Our results make a significant contribution to the understanding of the mechanisms of ketogenic diet action. FINANCIAL SUPPORT: This research is supported by the National Science Center grant no. 2017/01/X/ NZ3/00984.
18

Global proteomic analysis of brain changes induced by 'lifestyle' modifications

33%
Nowacka-Chmielewska M., Liskiewicz D., Liskiewicz A., Marczak L., Wojakowska A., Przybyla M., Grabowski M., Jablonska K., Barski J. J., Malecki A.
Acta Neurobiologiae Experimentalis
|
2019
|
tom 79
|
nr Suppl.1
In the pathogenesis of central nervous system (CNS) disorders, an increasingly important role is attributed recently to unhealthy lifestyle, which consists primarily of a high caloric diet (i.e., western), chronic exposure to stress, and lack of physical activity. However, the mechanisms responsible for energy metabolism impairment induced by unhealthy lifestyles compromising CNS functions are poorly understood. Research on the effects of physical activity on the CNS is especially important, because it may result in the development of new methods of therapy inspired by natural protective mechanisms. In our study we employed a new and rarely used approach – a forced running wheel. The lack of electrical stimulus in the aforementioned system successfully makes a breakthrough in the study of animal physical activity. Physiological and behavioral responses of the organism to stress are closely related to sex. Epidemiological studies indicate that women are more vulnerable to the adverse effects of stress and despite that, most of the experimental studies are conveyed on male animals. The investigations were carried on female rats. The main goal of our study was to verify the hypothesis that regular exercise may reduce the disturbances induced by lifestyle modifications, like western diet and/or stress exposure. Adult female rats were fed with the prepared chow reproducing the human western diet and/or subjected to a stress induced by social instability. This stress protocol is characterized by a low degree of invasiveness. To evaluate if regular physical activity may reduce the adverse effects caused by diet and stress, female rats were additionally subjected to the procedure of forced physical activity. A proteomic analysis was conducted on samples obtained from the frontal cortex – a region that plays an important role in cognitive processes as well as is involved in the mechanisms engaged in the response to stress.
19

Komentarze rynkowe

32%
Ohler Z., Czechowski M., Malecki A., Nowak W.
Top Agrar Polska
|
2004
|
nr 03
16
20

Anxiolytic effect of physical activity and cerebral accumulation of saturated fatty acids

27%
Liskiewicz A., Przybyla M., Wojakowska A., Marczak L., Bogus K., Nowacka-Chmielewska M., Liskiewicz D., Malecki A., Barski J. J., Lewin-Kowalik J., Toborek M.
Acta Neurobiologiae Experimentalis
|
2019
|
tom 79
|
nr Suppl.1
INTRODUCTION: The broad spectrum of the positive effects of physical activity on brain functioning is well acknowledged. Among others, it induces an improvement in mood, and a part of the rodent studies support this thesis by showing anxiolytic effects of exercise. However, the mechanism of this behavioral modification is not clear. Changes in brain metabolism may contribute to the generation of complex brain disorder phenotypes; thus, metabolomics have proven to be useful tools in studies on the central nervous system. AIM(S): The discrimination of anxiolytic level and metabolomics changes in the brain were evaluated in this study. METHOD(S): Voluntary running mice were subjected to a battery of behavioral tests (Open Field, Elevated Plus Maze, Dark/Light Box) commonly used to measure anxiety levels. Simultaneously, GC/MS analysis of hippocampal and cortical samples was performed for metabolome profiling of the running mice. RESULTS: The exercised animals showed anxiolytic behavior. Voluntary running caused an accumulation of saturated fatty acids, such as myrisitc, palmitic, heptadecanoic, and stearic acids, in the hippocampus and cortex of running mice. CONCLUSIONS: A striking observation in the present study is that a profile of saturated fatty acids that accumulates in the hippocampi and cortex of the running mice is consistent with the mixture of fatty acids that was identified as causing anxiolytic-like effects when administered to rodents.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.