Modulation of Ca2+ ion flux through mitochondrial membrane of the rat brain steam synaptosomes by 17β-estradiol

In the present study the modulation of Ca2+ ion flux in the synaptosomal mitochondria isolated from the ovariectyomized rat Brain Steam and the possible roll of membrane bound estradiol was examined. Physiological concentrations of 17β-estradiol binds specifically to isolated mitochondria (Vmax 3.37± 0.25 pmol/mg protein, Km 1.85± 0.06 nmol/l of free estradiol). Addition of 17β-estradiol (10 pmol/l - 1 nmol/ l) in vitro decreased mitochondrial calcium ion efflux significantly (25%) after 10 minutes. Modulation of calcium ion efflux and mitochondrial ion retention may be the way that 17β-estradiol (E2) exerts its role in the nerve cell homeostasis.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Effect of EDTA on the inhibition of rat myometrial ecto-atpase activity in the presence of heavy metal ions I. Mercury

The effects of increasing concentrations of HgCl2 on rat uterine plasma membrane ecto-ATPase activity, in presence and absence of ethylenediamine tetra acetic acid (EDTA) were studied. The aim was to examine the ability of EDTA to prevent mercury induced inhibition of ecto-ATPase activity. Our results show that addition of 1mmol/l EDTA to the reaction mixture potentiates Hg2+ induced inhibition of enzyme activity. We may concluded that formation of the HgEDTA complex increased capacity of Hg2+ to inhibit enzyme activity.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Properties of grape seed Proanthocyanidins and quercetin in human lymphocytes

This study addresses the in vitro protective effects of proanthocyanidins and quercetin on the frequency of micronuclei with reference to the antioxidant status of cultured human lymphocytes also subjected to 2 Gy of gamma-radiation. Treatment of lymphocytes with proanthocyanidins induced a significant decrease in the frequency of micronuclei and reduction of malonyldialdehyde production, as well as increased catalase and glutathione S-transferase activity Quercetin induces a higher incidence of micronuclei and production of malonyldialdehyde. The seven-fold increase of micronuclei frequency induced by a therapeutic dose of gamma-radiation was decreased in the presence of proanthocyanidins. These results demonstrate that proanthocyanidins may be important in the prevention of ROS-induced oxidative lymphocyte damage by decreasing DNA damage, lowering membrane lipid peroxidation, and increasing the activity AOP enzymes, as well as by reducing the level of gamma-radiation-induced DNA damage. Our results support the potential benefits of proanthocyanidins as efficient antioxidants and radioprotectors

Different sensibility of ecto-ATPase from brain and ovary to Cu2+ and Zn2+

Ions of zinc and cooper represents micro elements present in all organisms but they can be accumulated in various tissues from the environment by food or pollution. In this work we examined the effects of chloride salts of Cu2+ and Zn2+ on the activity of ecto-ATPase, integral plasma membrane protein, in brain and ovarian cells. Both ions exhibit similar effects on brain or ovarian enzyme activity. Cooper in brain and ovary totally inhibits enzyme activity at the concentration of 1 mM and 0.1 M respectively. IC50 for brain is 36 µM while in ovary it is 192 µM. Zinc inhibits in both tissues 50% of the control enzyme activity at concentrations of 1 mM in brain and 0.1 M in ovary with IC50 of 1mM and 14 mM respectively. These metals possess an affinity for -SH groups in the enzyme protein, may replace Mg2+ in enzyme substrate, MgATP or to bind for enzyme substrate site. According to the total inhibition of ecto-ATPase activity by Cu 2+, it may be proposed that its site of action is on the substrate or substrate binding site, while Zn2+ modulates enzyme activity by acting on the –SH or S-S groups of the enzyme. Inhibiting or decreasing ecto-ATPase activity in brain and ovary, these two metal ions may be toxic and seriously disturb the proper functioning of the investigated tissues.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effect of EDTA on the inhibition of rat myometrial ecto-ATPase activity in the presence of heavy metal ions II. cadmium

The effects of ethylenediamine tetraacetic acid (EDTA) on the CdCl2 cell toxicity was examined on rat myometrium. Activity of plasma membrane ecto-ATPase, as modulator of purinergic signaling in the presence of increasing concentrations of cadmium salt and in the presence or absence of EDTA were studied. The EDTA, chelating cadmium ions decrease inhibitory cadmium potency by increasing half-maximum inhibitory activities of this ion.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Efficiency analysis of higher education in Croatia

Kvalitetna organizacija sustava obrazovanja sve je veći faktor u ostvarivanju kontinuiranog napredovanja gospodarstva. Upravo zbog toga je važno mjeriti kvalitetu obrazovanja kroz brojne pokazatelje učinkovitosti. Jedan od pokazatelja kvalitete visokog obrazovanja je i praćenje kretanja broja upisanih i završenih studenata na visokim učilištima koji jasno prikazuje povećava li se ili smanjuje broj studenata koji upisuju odnosno završavaju studije. U posljednjih nekoliko godina Hrvatska sve više ulaže u povećanje kvalitete visokog obrazovanja, djelomično kroz primjenu Bolonjskog procesa, a djelomično kroz interne analize samih ustanova visokog obrazovanja. Ulaganje u kvalitetu rezultiralo je pozitivnim stopama završavanja studija no unatoč tome, Hrvatska i dalje zaostaje za Europom prema udjelu visokoobrazovanih. Analiza učinkovitosti visokog obrazovanja pokazuje da Hrvatska kontinuirano povećava svoj udio visokoobrazovanih no da bi se dosegao prosjek Europske Unije, daljnji napori u poboljšanju obrazovne slike Republike Hrvatske i dalje predstavljaju nužnost.Quality organization of the education system is a growing factor in achieving continuous economic progress. Therefore it is important to measure quality of education through a number of indicators of effectiveness. One of the indicators of quality of higher education is also to monitor changes in the number of enrolled and graduated students at higher education institutions that clearly shows whether the number of students who enroll and complete their studies increases or decreases. In a last few years Croatia is investing in increasing quality of higher education, partly through implementation of Bologna process, and partly through internal analysis of institutions of higher education. Investing in quality resulted with positive completion rate but despite that, Croatia is still behind Europe according to the share of highly educated. Efficiency analysis of higher education shows that Croatia is continuously increasing its share of highly educated but in order to reach the average of European Union, further efforts in improving educational image still represent a necessity

Različiti učinci samih hlapljivih anestetika ili u kombinaciji s gama-zračenjem od 1 i 2 Gy in vivo na DNA mišje jetre: preliminarno istraživanje

As the number of radiotherapy and radiology diagnostic procedures increases from year to year, so does the use of general volatile anaesthesia (VA). Although considered safe, VA exposure can cause different adverse effects and, in combination with ionising radiation (IR), can also cause synergistic effects. However, little is known about DNA damage incurred by this combination at doses applied in a single radiotherapy treatment. To learn more about it, we assessed DNA damage and repair response in the liver tissue of Swiss albino male mice following exposure to isoflurane (I), sevoflurane (S), or halothane (H) alone or in combination with 1 or 2 Gy irradiation using the comet assay. Samples were taken immediately (0 h) and 2, 6, and 24 h after exposure. Compared to control, the highest DNA damage was found in mice receiving halothane alone or in combination with 1 or 2 Gy IR treatments. Sevoflurane and isoflurane displayed protective effects against 1 Gy IR, while with 2 Gy IR the first adverse effects appeared at 24 h post-exposure. Although VA effects depend on liver metabolism, the detection of unrepaired DNA damage 24 h after combined exposure with 2 Gy IR indicates that we need to look further into the combined effects of VA and IR on genome stability and include a longer time frame than 24 h for single exposure as well as repeated exposure as a more realistic scenario in radiotherapy treatment.Kako se broj radioterapijskih i radioloških dijagnostičkih postupaka iz godine u godinu povećava, tako raste i primjena hlapljivih anestetika za opću anesteziju. Iako se smatralo sigurnim, izlaganje hlapljivim anesteticima može izazvati različite štetne učinke, a u kombinaciji s ionizirajućim zračenjem može izazvati i sinergijske učinke. Međutim, malo se zna o oštećenju DNA koje uzrokuje ova kombinacija u dozama primijenjenima u jednom izlaganju u radioterapiji. Kako bismo saznali više o tome, alkalnim komet-testom analizirali smo oštećenje DNA i odgovor na popravak u jetrenom tkivu muških Swiss albino miševa nakon izlaganja samo izofluranu, sevofluranu ili halotanu, odnosno u kombinaciji sa zračenjem od 1 ili 2 Gy. Uzorci su uzeti odmah (0 h) te 2, 6 i 24 sata nakon izlaganja. U usporedbi s kontrolom, najveća oštećenja DNA utvrđena su u miševa koji su primili halotan, sam ili u kombinaciji sa zračenjem od 1 ili 2 Gy. Sevofluran i izofluran pokazali su zaštitne učinke nakon izlaganja zračenju od 1 Gy, a pri 2 Gy prve nuspojave pojavile su se 24 sata nakon izlaganja. Iako učinci hlapljivih anestetika ovise o metabolizmu jetre, otkrivanje nepopravljenog oštećenja DNA 24 sata nakon kombinirane izloženosti sa zračenjem od 2 Gy upućuje na to da trebamo nastaviti istraživati kombinirane učinke hlapljivih anestetika i ionizirajućega zračenja na stabilnost genoma i obuhvatiti šire razdoblje nakon jednokratne izloženosti (duže od 24 sata). Također treba obuhvatiti višekratna izlaganja kao realističniji scenarij u liječenju radioterapijom

Primjena alkalnog kometnog testa u istraživanju radioprotektivnih učinaka alkoholnog ekstrakta propolisa i kvercetina na miševima ozračenim gama-zračenjem

The aim of this study was to assess radioprotective effects of quercetin and the ethanolic extract of propolis (EEP) in CBA mice exposed to a single radiation dose 4 Gy (60Co). The mice were treated with 100 mg kg-1 quercetin or EEP a day for three consecutive days either before (pre-treatment) or after gamma-irradiation (therapy). Leukocyte count was determined in blood drawn from the tail vein, and DNA damage in leukocytes was assessed using the alkaline comet assay. Genotoxic effects of the test compunds were also evaluated in non-irradiated mice. The levels of radioprotection provided by both test compounds were compared with those established in mice that were given chemical radioprotector S-(2-Aminoethyl)isothiouronium bromide hydrobromide (AET). Mice that received pre-treatment were less sensitive to irradiation. Mice given the post-irradiation therapy showed a slight but not significant increase in total leukocyte count over irradiated negative control. Quercetin showed better protective properties than EEP in both pre-treatment and therapy, and activated a higher number of leukocytes in non-irradiated mice. The alkaline comet assay suggests that both natural compounds, especially when given as pre-treatment, protect against primary leukocyte DNA damage in mice. At tested concentrations, EEP and quercetin were not genotoxic to non-irradiated mice. AET, however, caused a slight but not significant increase in DNA damage. Although the results of this study show the radioprotective potential of the test compounds, further investigation is needed to clarify the underlying protection mechanisms.Na miševima soja CBA istraženi su radioprotektivni učinci alkoholnog ekstrakta propolisa (AEP) i flavonoida kvercetina primijenjenih u obliku predtretmana i terapije usporedo s izlaganjem gama-zračenju iz izvora 60Co, doze 4 Gy. Testirane tvari injicirane su miševima intraperitonealno u dozi od 100 mg kg-1 tijekom tri uzastopna dana. Nakon završetka pokusa u uzorcima krvi ozračenih miševa utvrđen je ukupni broj leukocita, a razina primarnih oštećenja u DNA izmjerena je primjenom alkalnog kometnog testa. Usporedo su istraženi i mogući genotoksični učinci testiranih tvari na neozračenim miševima. Razine radioprotekcije koju pružaju propolis i kvercetin uspoređene su sa sintetskim radioprotektorom AET-om (S-(2-aminoetil)izotiouronij bromid hidrobromid). Predtretman miševa bilo kojim oblikom radioprotektora pridonosi boljem odgovoru na zračenje. U miševa koji su primili radioprotektore u obliku terapije uočen je mali porast ukupnog broja leukocita u odnosu na ozračenu negativnu kontrolu. Kvercetin je pružio bolju zaštitu od zračenja nego AEP, i u predtretmanu i terapiji, a u neozračenih miševa potaknuo je oslobađanje većeg broja leukocita u odnosu na negativnu kontrolu. Rezultati istraživanja upućuju na to da propolis i njegove fl avonoidne sastavnice, osobito ako su primijenjene prije ozračivanja, mogu učinkovito zaštititi miševe od štetnih učinaka ionizirajućeg zračenja i smanjiti razinu primarnih oštećenja DNA u leukocitima. AEP i kvercetin u testiranim dozama nisu bili genotoksični, za razliku od AET-a koji je izazvao mali porast razine oštećenja DNA u leukocitima neozračenih miševa. Iako rezultati istraživanja upućuju na radioprotektivne učinke testiranih prirodnih spojeva, radi pojašnjenja pretpostavljenih mehanizama radioprotekcije potrebna su daljnja istraživanja

Effectivity of flavonoids on animal model psoriasis – thermographic evaluation

Background and purpose: Psoriasiform lesions are characterized by hyperproliferation and aberrant differentiation of epidermal keratinocytes, accompanied by inflammation, leading to a disrupted skin barrier with an abnormal stratum corneum. Psoriasis is a chronic inflammatory disease whose etiopathogenesis has not yet been fully resolved, and therefore there is no standardized therapeutical approach. This study examined the possible positive effects of propolis and its polyphenolic/flavonoid compounds on animal model psoriasis, induced by the Di-n-Propyl Disulfide iritant (PPD), and the possibility to assess usefulness of thermography in psoriatic lesion regression. Material and methods: We monitored the inflammation process by monitoring the total number of inflammatory cells in peritoneal cavity, macrophage spreading index and thermographic scanning. Thermographic is scanning an effective and simplemethod which reproducibly records thermographic images of the examined area. The tested animals were divided into sixteen groups and locally processed during five days with PPD, water and ethanolic extract (WSDP or EEP) of propolis preparations and flavonoids (Epigallocatechin 3-gallate, Quercetin, Chrisin, Curcumin). Results: The results of thermal imaging showed no statistically significant differences in temperature changes on skin locuses of psoriasis formed lesions among the examined groups. The total number of inflammatory cells in peritoneal cavity and the macrophage spreading index were reduced in psoriatic mice treated with test components. Conclusions: These results demonstrate that topical application of propolis and the flavonoids present in propolis may improve psoriatic-like skin lesions by suppressing functional activity of macrophages and ROS production. Taken toghether, it is suggested that propolis and flavonoids offer some protection against psoriatic complications through their roles as inhibitors of inflammation and as free radical scavengers. Thermal imaging was realistic, and can be applicable in examining the inflammatory process in psoriasis and in evaluating the effectiveness of tested substances