Wyniki wyszukiwania

1

Malatonin in humans

100%

Karasek M., Winczyk K.

Journal of Physiology and Pharmacology. Supplement

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2006

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tom 57

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nr 5

19-39

Melatonin, the hormone of the pineal gland, received a great deal of attention in the last decade because of its availability as over-the-counter drug or food supplement in some countries and suggested role in many vital physiological processes. Melatonin secretion is not restricted to mammals but is also produced in nonmammalian vertebrates, in some invertebrates, and in many plants, with the same molecular structure. The synthesis of melatonin is strictly controlled by lighting conditions and shows a clear circadian rhythm with low values during the daytime and significant increase at night. In this survey the basic data on melatonin significance in human physiology and in pathological processes as well as its possible thrapeutic significance are reviewed and discussed.

2

Circadian variations of histamine binding to lymphocytes and neutrophils and skin reactivity to histamine in atopic and healthy subjects

100%

Zak-Nejmark T., Nowak I. A., Kraus-Filarska M.

Archivum Immunologiae et Therapiae Experimentalis

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2006

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tom 54

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nr 4

3

Developmental changes in heart contractile activity during diapause and postdiapause period in pupae of Hyles euphorbiae L.

100%

Waclawska A., Szyngwelski R., Rosinski G.

Pestycydy

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2004

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nr 3-4

4

Influence of symplasmic isolation on circadian rhythm of 3 H leucine incorporation to manubrial cells of Chara vulgaris antheridia

100%

Kwiatkowska M., Poplonska K., Gosek A., Kazmierczak A.

Acta Biologica Cracoviensia. Series Botanica et Zoologia. Supplement

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1997

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tom 39

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nr 1

5

Circadian rhythm in the subcommissural organ and paraphysis cerebri of the yellow-bellied toad, Bombina variegata [L.], under laboratory conditions

100%

Sura P.

Folia Biologica

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1992

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tom 40

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nr 1-2

6

Electrophysiology and pharmacology of the optic input to the rat intergeniculate leaflet in vitro

84%

Blasiak A., Blasiak T., Lewandowski M. H.

Journal of Physiology and Pharmacology

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2009

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tom 60

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nr 1

171-180

The mammalian intergeniculate leaflet (IGL) of the thalamus is a neuronal element of the circadian timing system, which receives direct photic input from the retina. The purpose of this study was to analyze responses of rat IGL neurons in vitro to optic tract stimulation and to identify neurotransmitters released from the terminals of retinal ganglion cells in this structure. Following optic tract stimulation, most of the responding IGL cells were excited and only a minority of them were inhibited. Neurons showing the excitatory response were tested in the presence of AP-5, a selective antagonist of NMDA receptors. In most cases the responses were only partially inhibited by the presence of AP-5. Complete disappearance of excitatory responses was achieved by adding CNQX, an AMPA/kainate receptor-selective antagonist, to the standard incubation fluid. Inhibitory responses were blocked or considerably attenuated in the presence of bicuculline, a GABAA receptor antagonist, in the ACSF. This study demonstrated that glutamate is the main neurotransmitter mediating optic tract input to the IGL, acting mainly via non-NMDA ionotropic receptors. It was also shown that NMDA and GABAA receptors are involved in passing photic input to the IGL, albeit to a much lesser extent.

7

Age-related circadian variations of cardiac and respiratory components of the carotid baroreflex in humans

84%

Klawe J. J., Tawil-Klawe M., Sikorski W., Szajnoch W., Jeske K.

Journal of Physiology and Pharmacology. Supplement

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2004

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tom 55

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nr 3

83-88

Our previous studies indicated the presence of a respiratory effector of carotid baroreceptor activation: the respiratory resistance. A brief decrease in respiratory resistance was observed in response to carotid baroreceptor activation. In the course of aging we found a decrease in the heart response to carotid baroreceptor activation and disappearance of the respiratory response. The aim of the present study was to determine whether the circadian variations of baroreflex sensitivity, as related to aging, are attributable to changes in cardiovascular and respiratory control in the elderly. We evaluated the cardiac responses and the reflex changes of the respiratory resistance to carotid baroreceptor activation every two hours in: 12 healthy male subjects aged 20-38 years, 6 male subjects aged 20-38 years and 6 male subjects aged 70-80 years. Two neck-chambers were used to produce a brief suction, applied to carotid sinus regions, activating the carotid baroreceptor. We found that the circadian courses of the cardiac and respiratory responses to baroreceptor activation were shifted down in the older groups of subjects, as compared with the younger ones. In the 50-80-year old subjects no respiratory response to carotid baroreceptor stimulation was observed. We further found that the impaired carotid baroreflex control of heart function and of respiratory resistance, observed in older subjects, reached a minimum between 3.00 and 7.00 hours in the morning. We conclude that this period is a risk time for the occurrence of cardiac disorders, especially for cardiac arrhythmias, and it is also the time of impaired reflex control of respiratory resistance.

8

Nocturnal resveratrol administration inhibits chemically induced breast cancer formation in rats

84%

Kiskova T., Demeckova V., Jendzelovska Z., Kiktava M., Venglovska K., Bohmdorfer M., Jager W., Thalhammer T.

Journal of Physiology and Pharmacology

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2017

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tom 68

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nr 6

9

The relationship between mitochondria function and circadian clock in peripheral oscillators

84%

Kazmierczak A., Schmitt K., Grimm A., Strosznajder J. B., Eckert A.

Acta Neurobiologiae Experimentalis

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2013

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tom 73

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nr 1

Circadian rhythms govern a wide variety of physical, behavioral and metabolic changes that follow a roughly 24-hour cycle, responding primarily to light and darkness in an organism’s environment. These are controlled by the circadian clock mechanism, where rhythm-generating mechanism is encoded by a transcription-translation feedback loop. Numerous studies have pointed to a cyclic relationship wherein the rhythm impacts metabolic activity and metabolism feeds back to impinge upon the rhythm. Mitochondria play a pivotal role in regulating cellular energy and were shown to be strategically positioned at the intersection between circadian rhythm and cell metabolism. Nevertheless little is known about their function in controlling the circadian rhythm. In our study, we investigated the involvement of circadian clock in mitochondrial function as well as mitochondria-dependent regulation of circadian clock. The study was carried out in primary human fibroblasts, an already established model to investigate molecular clock mechanisms in vitro. We have found that mitochondria activity as well as network activities showed rhythmic changes within 24 hours. Circadian pattern was detected for mitochondrial ROS including superoxide anion production. A significant 24-hour oscillation was found for cellular redox state. Furthermore, mitochondrial ATP levels were rhythmic and the maximum of ATP production paralleled the peak of mitochondrial ROS level and the mitochondrial network formation. Circadian rhythm was also detected for calcium ions concentration. Increase of ATP synthesis as well as changes in calcium and ROS level activated AMP-dependent protein kinase (AMPK). We have found that in primary human fibroblasts AMPK protein level and activity fluctuate in an antiphase relationship with rhythmic ATP production. Summarizing, our data provide the evidence for circadian regulation of mitochondrial dynamics and suggest that changes of mitochondrial activity may directly influence cellular clock. Supported by grants from Sciex 10. 258 to A.K. as well as Swiss National foundation (SNF No 310030_122572) and Synapsis Foundation to A.E

10

Alzheimer’s amyloid beta peptides disturb circadian oscillations of intracellular calcium concentration

84%

Kazmierczak A., Schmitt K., Grimm A., Strosznajder J. B., Eckert A.

Acta Neurobiologiae Experimentalis

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2013

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tom 73

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nr 1

It is postulated that disturbances in calcium homeostasis play an important role in pathogenesis of Alzheimer’s disease (AD). Changes of neuronal calcium concentration are responsible for the oxidative stress as well as altered metabolism and production of amyloid-beta peptides (Aβ). Aβ may further exacerbate calcium dysregulation, causing synaptic dysfunction, neurodegeneration and cognitive impairment. Recent data indicate that AD is associated with disturbances of circadian rhythm in the patients. However, till now nothing is known about the molecular mechanisms involved in AD-related circadian clock alterations. In our study we investigated the effect of Aβ peptides on the rhythmic oscillation of cytosolic and mitochondrial calcium levels. To investigate molecular clock mechanisms, the studies we carried out in human primary skin fibroblasts, a previously established experimental model. Our data showed circadian rhythm of calcium ions concentration in cytosol and mitochondria. Moreover we observed circadian oscillation of ROS formation and redox potential. Treatment with Aβ fibrils at the concentration of 0.5 µM disturbed cytosolic calcium oscillations and mitochondrial redox state. Studying mechanisms involved in this phenomenon indicated that Aβ did not affect ER calcium stores, but induced changes of calcium influx mediated by purinergic P2X7 receptor. The specific antagonist of P2X7 receptor Brillant Blue G abolished negative impact of Aβ and restored calcium circadian rhythm. Summarizing, our results indicate that Aβ may play a significant role in disturbances of circadian calcium oscillation, suggesting the importance of this phenomenon in ADrelated changes in biological clock. Supported by grants from Sciex 10. 258 to A.K. as well as Swiss National foundation (SNF No 310030_122572) and Synapsis Foundation to A.E.

11

Mass spectrometric analysis of PDF [pigment-dispersing factor] neurons of Periplaneta americana L.

84%

Neupert S.

Pestycydy

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2005

|

nr 3

183-187

12

Circadian rhythms of melatonin and cortisol in manifest Huntington's disease and in acute cortical ischemic stroke

84%

Adamczak-Ratajczak A., Kupsz J., Owecki M., Zielonka D., Sowinska A., Checinska-Maciejewska Z., Krauss H., Michalak S., Gibas-Dorna M.

Journal of Physiology and Pharmacology

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2017

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tom 68

|

nr 4

13

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The value of interdisciplinary research: lessons from the 2017 Nobel Prize in chronobiology

84%

Giebultowicz J. M.

Medical Science Pulse

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2018

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tom 12

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nr 1

Since 1901, the Nobel Prize has been awarded to scientists who have made the most important discoveries for the benefit of humanity. The 2017 Nobel Prize in Physiology or Medicine was awarded jointly to Jeffrey C. Hall, Michael Rosbash and Michael W. Young “for their discoveries of molecular mechanisms controlling the circadian rhythm.” It may be surprising to learn that those three scientists dedicated their entire careers to research on the fruit fly, Drosophila melanogaster. However, as their studies progressed, it became increasingly clear that the mechanism of the biological clock that they discovered in Drosophila is very similar to a timekeeping mechanism present in mammals, including humans. Through interdisciplinary work between scientists performing basic research on model organisms and doctors working in medical schools, we have learned over time that daily rhythms support human health while disruption of these rhythms is associated with a range of pathological disorders such as cardiovascular problems, metabolic, neurological, and many other diseases. This short review will highlight critical milestones on the way to understanding biological clocks, focusing on the roles played by the three Nobel Prize winners.

14

Circadian rhythms of ground living spiders: mechanisms of coexistence strategy based on the body size

84%

Krumpalova Z., Tuf I. H.

Polish Journal of Ecology

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2013

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tom 61

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nr 3

Circadian rhythms of activity are one of the many cases of the multidimensional mechanisms of species coexistence. Except of others, the mechanisms of coexistence strategy of spiders involve habitat, seasonal occurrence, food offers and body size of spiders. Circadian rhythm of activity of ground living spiders in floodplain forest and clearcut along the Morava River in the Litovelské Pomoraví Protected Landscape Area (Czech Republic, Central Europe) was studied. Activity of whole community was asymmetrical, diurnal activity was more frequent than nocturnal. Abundant species were analysed closely. Patterns of similarity in syntopic spider groups suggested the body size is significant factor influencing their circadian activity. We found out the predominantly small species achieved bimodal pattern of activity, influenced by the different activity of males and females. Generally we can conclude that spiders smaller than 5 mm were active during late night-morning and spiders bigger than 5 mm were active during afternoon and evening. This pattern was associated with changes of temperature of soil surface – big spiders were active during warmer parts of day. The presented data provide evidence of body-size differences among the spiders enable their coexistence in assemblages.

15

Circadian activity rhythm in sheep and goats housed in stable conditions

84%

Piccione G., Giannetto C., Casella S., Caola G.

Folia Biologica

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2008

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tom 56

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nr 3-4

133-137

16

Effects of electrode placement relative to the cardiac muscle on ECG pattern in carp [Cyprinus carpio L.]

84%

Klyszejko B., Dziaman R., Hajek G.

Acta Ichthyologica et Piscatoria

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2001

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tom 31

|

nr 1

Effects of electrode placement on the ECG quality were studied in 200-1500 g individual weight carp. Out of 12 combinations of lead placement relative to the cardiac muscle, 3 were found to produce the most legible, reproducible ECG′s.

17

Circadian rhythm of locomotor and motor activity in laboratory mice. The influence of light and neuropeptide administration. III. Neuropeptide Y

84%

Lach H., Srebro Z.

Acta Biologica Cracoviensia. Series Zoologia

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1995

|

tom 37

18

Circadian variation of corticosterone in adrenal vein blood in rats exposed to different light conditions

84%

Ostrowska Z., Zwirska-Korczala K., Buntner B., Kos-Kudla B.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1993

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tom 41

|

nr 1

19

Circadian rhythm of locomotor and motor activity in laboratory mice. The influence of light and neuropeptide administration. I. Oxytocin

84%

Lach H., Srebro Z.

Acta Biologica Cracoviensia. Series Zoologia

|

1995

|

tom 37

20

Circadian rhythm in the subcommissural organ of the frog Rana kl. esculenta under constant darkness

84%

Sura P.

Acta Biologica Cracoviensia. Series Zoologia

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2000

|

tom 42

Ograniczanie wyników

Malatonin in humans

Circadian variations of histamine binding to lymphocytes and neutrophils and skin reactivity to histamine in atopic and healthy subjects

Developmental changes in heart contractile activity during diapause and postdiapause period in pupae of Hyles euphorbiae L.

Influence of symplasmic isolation on circadian rhythm of 3 H leucine incorporation to manubrial cells of Chara vulgaris antheridia

Circadian rhythm in the subcommissural organ and paraphysis cerebri of the yellow-bellied toad, Bombina variegata [L.], under laboratory conditions

Electrophysiology and pharmacology of the optic input to the rat intergeniculate leaflet in vitro

Age-related circadian variations of cardiac and respiratory components of the carotid baroreflex in humans

Nocturnal resveratrol administration inhibits chemically induced breast cancer formation in rats

The relationship between mitochondria function and circadian clock in peripheral oscillators