Inactivation of melanoma cells irradiated with gamma rays and low energy protons

13th Balkan biochemical Biophysical Days and Meeting on Metabolic Disorders, October 12.-15., 2003, Kusadasi, Turke

Pellets from long-eared owls (asio otus) as indicators of soil quality

Pellets from Long-Eared Owls (Asio otus) were collected from four localities in the city and in the vicinity of Belgrade. The element content in the pellets was analyzed. The results indicate that owl pellets may be useful for monitoring environmental conditions, specifically soil quality

Cyclin D1 overexpression induces global transcriptional downregulation in lymphoid neosplasms

Cyclin D1 is an oncogene frequently overexpressed in human cancers that has a dual function as cell cycle and transcriptional regulator, although the latter is widely unexplored. Here, we investigated the transcriptional role of cyclin D1 in lymphoid tumor cells with cyclin D1 oncogenic overexpression. Cyclin D1 showed widespread binding to the promoters of most actively transcribed genes, and the promoter occupancy positively correlated with the transcriptional output of targeted genes. Despite this association, the overexpression of cyclin D1 in lymphoid cells led to a global transcriptional downmodulation that was proportional to cyclin D1 levels. This cyclin D1-dependent global transcriptional downregulation was associated with a reduced nascent transcription and an accumulation of promoter-proximal paused RNA polymerase II (Pol II) that colocalized with cyclin D1. Concordantly, cyclin D1 overexpression promoted an increase in the Poll II pausing index. This transcriptional impairment seems to be mediated by the interaction of cyclin D1 with the transcription machinery. In addition, cyclin D1 overexpression sensitized cells to transcription inhibitors, revealing a synthetic lethality interaction that was also observed in primary mantle cell lymphoma cases. This finding of global transcriptional dysregulation expands the known functions of oncogenic cyclin D1 and suggests the therapeutic potential of targeting the transcriptional machinery in cyclin D1-overexpressing tumors

Estradiol affects calcium transport across mitochondrial membrane in different brain regions

The in vitro effect of estradiol on flux of Ca2+ in the synaptosomal mitochondria from nucleus caudatus and hippocampus of chronically ovariectomized female rats was examined. No effect of estradiol on Ca2+, influx through ruthenium red-sensitive channels was found. Estradiol, at a concentration of 0.05-5 nmol/L for nucleus caudatus and 0.5-5 nmol/L for the hippocampus, decreased Na-dependent Ca2+ efflux about 25%.22nd International Biophysics Symposium, Oct 09-14, 2004, Belgrade, Serbi

Content of microelements in the rat pineal gland at different ages and the effects of selenium supplementation

The mammalian pineal gland regulates a number of important physiological processes. In this paper we report changes in the content of iron (Fe), zinc (Zn), copper (Cu), and selenium (Se) in the male rat pineal glands at 4, 5, 8, and 12 months of age. The effect of Se supplementation in drinking water on the content of pineal gland microelements was also studied. Selenium (Se)-dependent changes in pineal gland reported in this study suggest novel physicochemical and biochemical properties of Se, an important element essential in the antioxidative processes, yet known to influence a number of endocrine processes

Rat pinealocyte reactive response to a long-term stress inducement

The pineal gland-reactive response to long-term multifactor stress inducement performed by 18 h immobilization was found in the occurrence of different pinealocyte forms-cells of the basal activity, functionally animated cells and cells assumed to be threatened by an irreversible injury. Functionally animated pinealocytes were recognized as entities of neuroendocrine-like and ependymal-like activities displaying an episode of their initially increased secretory activity determined by Golgi apparatus and succeeded by a period determined by the storage of compounds arising from the cisterns of the granular reticulum. The domination of the pinealocytes with neuroendocrine-like activity was considered to evince a stimulated, peptidergic-mediated pineal gland activity. The adrenocorticotropic hormone-reactive secretion, employed as the evaluation parameter in morphofunctional observations, corroborated the morphologically estimated increased pineal gland activity in long-term stress inducement. Copyright (C) 1996 IBRO. Published by Elsevier Science Ltd

Effects of metal ions on Mg2+-ATPase activity in plasma membranes isolated from the rat uterus

In this study, we investigated the in vitro effects of metal ions on Mg2+-ATPase activity in isolated membranes from rat uterus. The effects of increasing concentrations of metal salts (CrCl2, CuSO4, HgCl2 and ZnSO4) show sigmoidal and almost complete inhibition relative to the control enzyme activity. According to the IC50, the ATPase possesses greater sensibility to Zn2+ GT Cu2+ congruent to Cr3+ congruent to Hg2+, while other metal salts exhibit the following inhibition: CdCl2 55%, CsCl 64.5% and SrCl2 58%. Here we demonstrated that the physicochemical properties of these metals are of importance in defining possible mechanisms of binding and decrease of enzyme activity

Effects of metal ions on plasma membrane Mg2+-ATPase in rat uterus and ovaries

The in vitro effects of cadmium and mercury were investigated on the Mg2+-ATPase activity of plasma membranes from the rat ovary and uterus. ATP hydrolyzing activities were significant and dose-dependent-inhibited in both plasma membrane preparations by both metals. According to the IC50 and apparent K-i, Cd2+ was most potent in the ovary, while Hg2+ was most potent in the uterus. In ovaries and uterus,Cd2+ inhibits competitively, while Hg2+ inhibits noncompetitively in both organs. The observed inhibition was a consequence of direct action of the chosen metal ions on the enzyme protein and by decreasing ATP hydrolysis, Hg2+ and Cd2+ may affect mammalian fertility.22nd International Biophysics Symposium, Oct 09-14, 2004, Belgrade, Serbi