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General Physiology and Biophysics

Tatiana Vovkun, Petro Yanchuk, Lidiya Shtanova, Stanislav Veselskiy, Natalia Filimonova, Anatoly Shalamay, Volodymyr Vedmid
Water-soluble analogue of quercetin, corvitin is used in patients with myocardial infarction as blocker of 5-lipoxygenase. However, its effects on secretion, lipid content and physico-chemical properties of bile have not been understood yet. We investigated the effect of corvitin, applied in different doses, on the level of bile flow, the content of bile free and esterified cholesterol, phospholipids, triacylglycerols, and free fatty acids. In order to determine stability of the bile colloidal system, we examined the relationship between different lipid components...
January 2018: General Physiology and Biophysics
Mahmoud S Sherif, Taha A Rehab, Zayed A Hamdia, Vladmir P Torchilin
Natural products are invaluable resource of anticancer drug discovery. They generally viewed as safe but weak, within the framework of nanotechnology, they can serve as template for potent anticancer drugs. We first evaluated the cytotoxic activity of different propolis extracts (water, 70% ethanol, absolute ethanol and hexane) in many cancer cell lines, then the solid nanoparticles from the organic solvent extracts were prepared and their cytotoxicity was evaluated as well. Finally, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes were prepared from the most cytotoxic organic solvent extract and their cytotoxicity was also evaluated...
January 2018: General Physiology and Biophysics
Ladislav Novotny, Leyla Sharaf, Mohammed E Abdel-Hamid, Julius Brtko
Triorganotins belong to toxic components present predominantly in antifouling paints for marine vessels. Tributyltin/triphenyltin at pico- or nanomolar concentrations in sea water are known to induce an irreversible sexual abnormality in females of over 190 marine species, an "imposex" phenomenon - the superimposition of male genitalia on a female. Moreover, trialkyltins and triaryltins function as potent nuclear retinoid X receptors (RXR) agonists. In mammals, triorganotin compounds induce immunosuppressive, metabolic, reproductive or developmental effects...
January 2018: General Physiology and Biophysics
Mina Ranjbaran, Mehri Kadkhodaee, Behjat Seifi, Reza Mirzaei, Parisa Ahghari
Hemorrhagic shock (HS) still has a high mortality rate and none of the known resuscitative regimens completely reverse its adverse outcomes. This study investigated the effects of different models of resuscitative therapy on the healing of organ damage in a HS model. Male Wistar rats were randomized into six groups: Sham, without HS induction; HS, without resuscitation; HS+Blood, resuscitation with the shed blood; HS+Blood+NS, resuscitation with blood and normal saline; HS+Blood+RL, resuscitation with blood and Ringer's lactate; EPO, erythropoietin was added to the blood and RL...
January 2018: General Physiology and Biophysics
Lukáš Hubčík, Dominika Galliková, Petra Pullmannová, Ľubica Lacinová, Zdena Sulová, Mária Hanulová, Sergio S Funari, Ferdinand Devínsky, Daniela Uhríková
DNA condensation, structure and transfection efficiency of complexes formed by gemini surfactants alkane-α,ω-diyl-bis(dodecyldimethylammonium bromide)s (CnGS12, n = 3, 6 and 12 is the number of alkane spacer carbons), dioleoylphosphatidylethanolamine (CnGS12/DOPE = 0.3 mol/mol) and DNA at low surface charge density were investigated through different techniques. Small angle X-ray diffraction showed a condensed lamellar phase with marked dependence of DNA-DNA distance on (+/-) charge ratio. High ionic strength of hydrating medium screens the interaction DNA - CnGS12/DOPE and complexed DNA represented maximally ~ 45-60% of total DNA in the solution as derived from fluorescence and UV-VIS spectroscopy...
January 2018: General Physiology and Biophysics
Ali Khalilimeybodi, Alireza Daneshmehr, Babak Sharif Kashani
Ca2+ is an important mediator in the β-adrenergic-induced cardiac hypertrophy. The β-adrenergic stimulation alters the Ca2+ transient characteristics including its oscillation frequency, diastolic and systolic levels which lead to the CaN activation and subsequent NFAT-dependent hypertrophic genes transcription. Moreover, β-adrenergic-induced alterations in PKA and GSK3β kinase activities in both the cytosol and the nucleus regulate NFAT nuclear translocation and contribute in its hypertrophic response...
January 2018: General Physiology and Biophysics
Ramzi A Al-Horani, Mukhallad Mohammad
This study investigated the noradrenergic contribution during the cutaneous vasoconstrictor response to local cooling in the leg and forearm. On each limb, one site was perfused with Yoh/Prop to block the postsynaptic adrenoceptors and another with Lactated Ringer's (control) using microdialysis. Blood flow was measured by Laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC) was calculated as LDF units divided by the mean arterial pressure. After baseline measures, skin was locally cooled to 24°C...
January 2018: General Physiology and Biophysics
Oľga Otrubová, Ladislav Turecký, Oľga Uličná, Pavol Janega, Ján Luha, Jana Muchová
N-acetyl-L-cysteine (NAC) is a drug routinely used in several health problems, e.g. liver damage. There is some information emerged on its negative effects in certain situations. The aim of our study was to examine its ability to influence liver damage induced by long-term burden. We induced liver damage by CCl4 (10 weeks) and monitored the impact of parallel NAC administration (daily 150 mg/kg of b.w.) on liver morphology and some biochemical parameters (triacylglycerols, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, bile acids, proteins, albumins and cholinesterase)...
January 2018: General Physiology and Biophysics
Zuzana Dankova, Pavol Zubor, Marian Grendar, Andrea Kapinova, Katarina Zelinova, Mariana Jagelkova, Alexandra Gondova, Karol Dokus, Michal Kalman, Zora Lasabova, Jan Danko
The fibroblast growth factor receptors (FGFRs) and Ras/mitogen activated protein (RAS/MAP) signalling cascades are the main molecular pathways involved in breast carcinogenesis. This study aims to determine the association between FGF10 (rs4415084 C>T), FGFR2 (rs2981582 C>T) and MAP3K1 (rs889312 A>C) gene polymorphisms and breast cancer, to analyse the discriminative ability of each SNP and to test the accuracy of the predictive breast cancer risk model which includes all SNPs. We conducted a case-control study of 170 women (57...
December 2017: General Physiology and Biophysics
Tatiana Matáková, Erika Halašová, Henrieta Škovierová, Anton Dzian, Dušan Dobrota, Mária Škereňová
Dihydropyrimidine dehydrogenase (DPD) acts as the first-step enzyme catabolizing pyrimidines in vivo. DPYD gene mutations interfere with the breakdown of uracil and thymine. Genetic variations of DPYD can cause an enzyme deficiency state, which results in severe toxicity or other adverse side effects such as DNA damage or RNA damage caused by imbalance of the nucleotide pool. Our case-control study investigates the possible association between seven DPYD gene polymophisms (rs1801267, rs72547602, rs1801160, rs3918290, rs1801159, rs1801158, rs1801265) and risk of colorectal cancer (CRC)...
December 2017: General Physiology and Biophysics
Henrieta Drobková, Jana Jurečeková, Marián Grendár, Ján Kliment, Erika Halašová, Ján Kliment
The aim of the study was to assess the relationship between preoperative circulating levels of total serum testosterone and pathological Gleason score and pathological stage in prostate cancer patients who underwent radical retropubic prostatectomy. The levels of total serum testosterone were measured in the morning just before surgery in a group of 201 prostate cancer patients. Multinomial logistic regression models were used to model the association between total preoperative testosterone (individually or in combination with other preoperative predictors such as age, PSA, clinical stage and biopsy Gleason score) and pathological Gleason score, pathological stage in prostate cancer patients...
December 2017: General Physiology and Biophysics
Andrea Štefaniková, Katarína Klačanová, Ivana Pilchová, Jozef Hatok, Peter Račay
Colorectal carcinoma (CRC) that represents one of the major causes for cancer-related death in humans is often associated with over-expression of anti-apoptotic proteins of Bcl-2 family. The aim of presented study was to determine the effect of ABT-737 inhibitor of anti-apoptotic proteins Bcl-2, Bcl-XL and Bcl-w as well as cyclin-dependent kinase 2 (CDK2) inhibitor SU9516 alone and in combination with ABT-737 on survival of colorectal cell lines HT29 and Caco-2. We have shown that both Caco-2 and HT29 cells that are relatively resistant to ABT-737 are also partially sensitive to SU9516, which increased sensitivity of Caco-2 but not HT29 cells to ABT-737...
December 2017: General Physiology and Biophysics
Petra Hnilicová, Romana Richterová, Ema Kantorová, Michal Bittšanský, Eva Baranovičová, Dušan Dobrota
In this study we evaluated clinical feasibility of proton magnetic resonance spectroscopy metabolite mapping (1H MRSI) by using 1.5 Tesla MR-scanner in 10 patients with high-grade glioblastoma. In vivo 1H MRSI performed with a relatively short scan time of 20 minutes enabled to obtain comprehensive information about metabolic changes in glioblastoma and adjacent tissues namely in the peritumoral edema, in the middle and solid part of the tumor, and in the normal-appearing brain tissue. Spectroscopically it was possible to identify initiation of neuronal cell death in the solid tumorous tissue via decreased N-acetyl-aspartate to creatine ratio (↓ tNAA/tCr) and expanding carcinogenesis reflected in elevated choline ratios (↑ tCho/tCr and tCho/tNAA)...
December 2017: General Physiology and Biophysics
Veronika Fialkova, Eva Vidomanova, Tomas Balharek, Juraj Marcinek, Erik Kudela, Sandra Hanysova, Jozef Visnovsky, Dusan Dobrota, Jozef Hatok
DNA methylation is a significant epigenetic modification which plays a key role in regulation of gene expression and influences functional changes in endometrial tissue. Aberrant DNA methylation changes result in deregulation of important apoptotic proteins during endometrial carcinogenesis and apoptosis resistance development. Evading apoptosis is still a major problem in the successful treatment of endometrial cancer patients. The aim of our study was to examine the promoter DNA methylation changes in 22 apoptosis-associated genes in endometrioid endometrial cancer patients, precancerous lesions and healthy tissue from various normal menstrual cycle phases using a unique pre-designed methylation platform...
December 2017: General Physiology and Biophysics
Radovan Murín, Eva Vidomanová, Bhavani S Kowtharapu, Jozef Hatok, Dušan Dobrota
Alterations in enzymatic activities underlying the cellular capacity to maintain functional S-adenosylmethionine (SAM) cycle are associated with modified levels of its constituents. Since SAM is the most prominent donor of methyl group for sustaining the methylation pattern of macromolecules by methyltransferases, its availability is an essential prerequisite for sustaining the methylation pattern of nucleic acids and proteins. In addition, increased intracellular concentrations of S-adenosylhomocysteine and homocysteine, another two constituents of SAM cycle, exerts an inhibitory effect on the enzymatic activity of methyltranferases...
December 2017: General Physiology and Biophysics
Jana Sopková, Eva Vidomanová, Ján Strnádel, Henrieta Škovierová, Erika Halašová
Statins are the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. This enzyme catalyzes conversion of HMG-CoA to mevalonate, which are the intermediates in cholesterol biosynthetic pathway. Statins also play an important role in carcinogenesis, because they are able to affect the cancer cell metabolism. Their effect has been observed in several cellular processes, such as angiogenesis, metastasis, apoptosis and cell proliferation. However, these effects are highly dependent on type of cancer and individual statins vary in their antitumor potential...
December 2017: General Physiology and Biophysics
Monika Kmeťová Sivoňová, Jana Jurečeková, Zuzana Tatarková, Peter Kaplán, Lucia Lichardusová, Jozef Hatok
Androgens play an important role during the development of both normal prostate epithelium and prostate cancer and variants of genes involved in androgen metabolism may be related to an increased risk of prostate disease. Cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) is a key regulatory enzyme in the steroidogenic pathway; it catalyses both 17α-hydroxylase and 17,20-lyase activities and is essential for the production of both androgens and glucocorticoids. In this review, we focus on the structure and enzymatic activity of CYP17A1 and the mechanism of modulation of CYP17A1 activities...
December 2017: General Physiology and Biophysics
Loay Kh M Hassouneh, Olga A Timofiychuk, Nataliya A Babenko
Malfunction of skeletal muscles and dysregulated turnover of sphingolipids in the insulin responsive tissues have been determined at old age. Present article investigates the role of acid sphingomyelinase (SMase)-dependent ceramide accumulation in reduction of the skeletal muscle sensitivity to insulin action at old age. The 3-, 12- and 24-month-old Wistar male rats were used in the experiments. The progressive increase of ceramide content and ceramide/sphingomyeline (SM) ratio was determined in the extensor digitorum longus (EDL) muscle during aging of rats...
November 10, 2017: General Physiology and Biophysics
José A Pacheco-Ortiz, Juan C Sánchez-Hernández, Leonardo Rodríguez-Sosa, Gabina Calderón-Rosete, Edgar Villagran-Vargas
The purpose of this paper is to explore the firing rate of the caudal photoreceptors (CPRs) from the sixth abdominal ganglion of the crayfish Cherax quadricarinatus. We use simultaneous extracellular recordings on left and right CPR in the isolated ganglion (n = 10). The CPRs showed an asymmetry in the spontaneous activity and light-induced response. In darkness, we observed one subgroup (70%) in which the left CPR (CPR-L) and right CPR (CPR-R) had spontaneous firing rates with a median of 18 impulses/s and 6 impulses/s, respectively...
November 10, 2017: General Physiology and Biophysics
Albert Martí, Juan J Pérez, Jordi Madrenas
The established action potential propagation mechanisms do not satisfactorily explain propagation on myelinated axons given the current knowledge of biological channels and membranes. The flow across ion channels presents two possible effects: the electric potential variations across the lipid bilayers (action potential) and the propagation of an electric field through the membrane inner part. The proposed mechanism is based on intra-membrane electric field propagation, this propagation can explain the action potential saltatory propagation and its constant delay independent of distance between Ranvier nodes in myelinated axons...
November 10, 2017: General Physiology and Biophysics
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