15 research outputs found
Manifestation of the spin textures in the thermopower of MnSi
To identify possible spin texture contributions to thermoelectric transport,
we present a detailed temperature and pressure dependence of thermopower in
MnSi, as well as a low-temperature study of in a magnetic field. We find
that reconstructs the phase diagram of MnSi encompassing the
Fermi liquid, partially ordered, and non-Fermi liquid phases. Our results
indicate that the latter two phases have essentially the same nature. In the
partially ordered phase, is strongly enhanced, which may be understood
as a spiral-fluctuation-driven phase. A low temperature upturn in
pertaining to the partial order phase persists up to the highest pressure, 24
kbar. Contrarily, a small suppression of is observed in the ordered
skyrmion lattice phase
Natural isolate Enterococcus faecalis BGPM3 produces an inducible extracellular proteinase
Enterococcus faecalis BGPM3 proizvodi proteinazu sposobnu da hidrolizuje ukupan kazein kao i frakcije Ī±s1-, Ī²-, i k-kazeina. Ova proteinaza, takoÄe, hidrolizuje želatin, ali ne deluje na denaturisani goveÄi serum albumin ili hemoglobin. Ustanovljeno je da se optimalna hidroliza kazeina u prisuetvu BGPM3 proteinaze postiže na pH 6.5, a njegova maksimalna hidroliza na 37Ā°C. Prisustvo proteolitiÄke aktivnosti u supernatantu, koji ne sadrži žive Äelije, ukazuje da izolat E. faecalis BGPM3 proizvodi ekstracelularnu proteinazu. Sinteza ove proteinaze se odigrava tokom celokupnog ciklusa rasta bakterije, pri Äemu se maksimum proizvodnje postiže u stacionarnoj fazi. Trstman BGPM3 proteinaze sa helatorima metalnih jona dovodi do potpunog gubitka proteolitiÄke aktivnosti. MeÄutim, moguÄe je povratiti proteolitiÄku aktivnost (do 75%) ako se tretiranom enzimu dodaju joni Zn2+ Å”to ukazuje da je BGPM3 proteinaza metaloenzim. ProteolitiÄka aktivnost ovog enzima je inhibirana jonima Cu2+, Äak i u prisustvu jona Zn2+. Eksperimentalni rezultati ukazuju da je proizvodnja BGPM3 proteinaze indudibilna, tj., dolazi do poveÄanja njene sinteze kada bakterija raste u prisustvu smeÅ”e oligopeptida (kazitona). Tako se dobija desetostruko poveÄanje proteolitiÄke aktivnosti u bezÄelijskom supernatantu kada se pripremi iz kulture koja sadrži kaziton. OdreÄivanje molekulske mase BGPM3 proteinaze je pokazalo da je to protein od oko 29 kDa.Enterococcus faecalis BGPM3 produces a proteinase that hydrolyzes total casein as well as Ī± s1-, Ī²-, and k-casein fractions. This proteinase was also able to hydrolyse gelatine, but not denatured bovine serum albumin and haemoglobin. The optimal pH of casein hydrolysis was 6.5 (determined at 30Ā°C). Maximum caseinolytic activity was obtained at 37Ā°C. The presence of proteolytic activity in cell-free supernatant strongly indicated that E. faecalis BGPM3 produces strictly extracellular proteinase. Proteinase production occurred through the growth cycle reaching a maximum at stationary phase. Pretreatment of the BGPM3 proteinase with metal ion chelators resulted in a total loss of proteolytic activity. Restoration of activity (75%) was obtained only with Zn2+ suggesting that the BGPM3 proteinase is zinc-metalloenzyme. Cu2+ even in the presence of Zn2+ inhibited proteolytic activity. It seems that production of proteinase is induced by oligopeptides (casitone), since 10-fold higher proteolytic activity was obtained in the cell-free supernatant prepared from the cultures containing casitone. The molecular mass determination revealed that extracellular BGPM3 proteinase has a molecular mass of about 29 kDa
Bioactivity and phenolics profile of aqueous and ethyl acetate extracts of Satureja kitaibelii Wierzb. ex Heuff. obtained by ultrasound-assisted extraction
The aim of the study was to investigate the biological activity and chemical composition of Satureja kitaibelii Wierzb. ex Heuff. LCāPDA/MS analyses for the aqueous extracts (A1-stem, leaves and flowers, A2-leaves and flowers) and ethyl-acetate extracts (E1-stem, leaves and flowers, E2-leaves and flowers) obtained by ultrasound-assisted extraction enabled the identification of thirty-four compounds. Quantitative analysis revealed that the aqueous extract obtained from leaves and flowers was the richest in total phenolic acids (65.36Ā mg/g) and flavonoids (21.17Ā mg/g). The total polyphenol content was the highest in the aqueous extract obtained from leaves and flowers (274 Ā± 2.4Ā mg Gallic Acid equivalents/g). The best antioxidant activity was observed for the same extract using the DPPH (SC50 20 Ā± 10Ā Āµg/mL), ABTS (2.834 Ā± 0.02Ā mg Ascorbic Acid/g), FRAP (1.922 Ā± 0.03Ā mmol Fe2+/mg), and total reducing power tests (16.4 Ā± 1.0Ā mg Ascorbic Acid/g). Both ethyl acetate extracts were the most active against strains of Bacillus cereus and Micrococcus flavus (MIC 1.70ā1.99Ā mg/mL and 1.99ā3.41Ā mg/mL, respectively). They were more efficient against Aspergillus ochraceus (MFC 0.86Ā mg/mL) and towards HeLa cell lines. All the obtained results implied the good potential of the investigated extracts to be used as effective preservatives and functional ingredients in food products and dietary supplements
Synthesis, characterization, biomolecular interactions, molecular docking, and in vitro and in vivo anticancer activities of novel ruthenium(III) Schiff base complexes
In order to discover new anticancer drugs, novel ruthenium(III) complexes [Ru(L)Cl(H2O)], where L is tetradentate Schiff base bis(acetylacetone)ethylendiimine (acacen, 1), bis(benzoylacetone)ethylendiimine (bzacen, 2), (acetylacetone)(benzoylaceton)ethylendiimine (acacbzacen, 3), bis(acetylacetone)propylendiimine (acacpn, 4), bis(benzoylacetone)propylendiimine (bzacpn, 5) or (acetylacetone)(benzoylaceton)propylendiimine (acacbzacpn, 6), were synthesized. The complexes 1 ā 6 were characterized by elemental analysis, molar conductometry, and by various spectroscopic techniques, such as UVāVis, IR, EPR, and ESI-MS. Based on in vitro DNA/BSA experiments, complexes 2 (bzacen) and 5 (bzacpn) with two aromatic rings showed the highest DNA/BSA-activity, suggesting that the presence of the aromatic ring on the tetradentate Schiff base ligand contributes to increased activity. Moreover, these two compounds showed the highest cytotoxic effects toward human, A549 and murine LLC1 lung cancer cells. These complexes altered the ratio of anti- and pro-apoptotic molecules and induced apoptosis of A549 cells. Further, complexes 2 and 5 reduced the percentage of Mcl1 and Bcl2 expressing LLC1 cells, induced their apoptotic death and exerted an antiproliferative effect against LLC1. Finally, complex 5 reduced the volume of mouse primary heterotopic Lewis lung cancer, while complex 2 reduced the incidence and mean number of metastases per lung. Additionally, molecular docking with DNA revealed that the reduced number of aromatic rings or their absence causes lower intercalative properties of the complexes in order: 2Ā >Ā 5Ā >Ā 6Ā >Ā 3Ā >Ā 4Ā >Ā 1. It was observed that conventional hydrogen bonds and hydrophobic interactions contribute to the stabilization of the structures of complex-DNA. A molecular docking study with BSA revealed a predominance of 1 ā 6 in binding affinity to the active site III, a third D-shaped hydrophobic pocket within subdomain IB
Retinoic acid affects basic cellular processes and SOX2 and SOX18 expression in breast carcinoma cells
Genetic and molecular heterogeneity, together with intrinsic and acquired resistance to therapy, represent the major obstacles to the successful treatment of different types of breast carcinoma. Increasing evidence demonstrates that SOX transcription factors in breast carcinomas could act both as oncogenes and tumor suppressors and have been associated with tumor stage and grade, poor prognosis, and therapy resistance. Both SOX2 and SOX18 overexpression has been correlated with poor prognosis in breast carcinomas, and these genes are recognized as potential antitumor targets. Our aim was to evaluate the effect of retinoic acid (RA), a well-known cyto-differentiating agent, on breast carcinoma cells in vitro and to investigate the potential of RA treatment to modify the expression of SOX2 and SOX18 genes. By applying various experimental approaches, we evaluated the effect of RA on basic cellular processes in SK-BR-3 and MCF7 breast carcinoma cell lines. We have shown that RA inhibits cell growth, reduces the number of Ki-67 positive cells, and causes cell-cycle arrest. RA effect was more prominent in SK-BR-3 cell line that lacks SOX2 expression, including a higher decrease in cell viability, reduction in colony formation, and significant remodeling of cellular structure. We have shown that RA treatment led to the downregulation of SOX2 expression in MCF7 cells and to the reduction of SOX18 expression in both cell lines. By functional analysis, we showed that the anti-proliferative effect of RA in both cell lines was not based on the activity of stemness marker SOX2, pointing to a SOX2-independent mechanism of action. The ability of RA to reduce SOX2/SOX18 expression raises the possibility that these genes can be used as biomarkers to distinguish RA-responders from non-responders. Together, our study shows that the response of breast carcinoma cell lines to RA treatment may vary, highlighting that the development of RA-based therapy should consider differences in breast carcinoma subtypes
IDENTIFICATION OF FACTORS INFLUENCING BIRTH WEIGHT, LENGTH, AND HEAD CIRCUMFERENCE
Newborn size at birth is an important indicator of fetal health, neonatal health, infant survival and childhood morbidity. The aim of our study was to assess and identify factors that significantly influence birth weight, length, and head circumference by performing a post hoc analysis of the data collected during the retrospective-prospective observational cohort study which was conducted at the Clinic for Gynecology and Obstetrics at the University Clinical Centre Kragujevac, Serbia. The influence of potential factors on birth weight, length, and head circumference was evaluated by multiple linear regression analysis. The study included 320 pregnant women and 332 newborns. Four factors had a significant negative effect on birth weight: smoking, twin pregnancy, use of methyldopa and corticosteroids during pregnancy. Smoking, twin pregnancy and corticosteroid use also had a significant negative effect on birth length. Negative effect on fetal head circumference at birth had smoking, use of corticosteroids and antibiotics during pregnancy. Maternal height and gestational age at birth showed a positive influence on fetal anthropometric measurements. Clinicians should pay attention to pregnant women with lower body height, twin pregnancy, who smoke and use corticosteroids, methyldopa and antibiotics
Potential preservation of dental pulp stem cells
Dental pulp stem cells (DPSCs) as postnatal stem cells have recently been described. They are clonogenic cells, capable for self-renewal with high proliferative potential. Their multilineage potential and plasticity enables their differentiation into different kind of cells, such as osteoblasts, chondrocytes, adipocytes, muscle cells, neural cells, odontoblasts, cementoblasts and ameloblasts. DPSCs are an important human stem cells source, especially in patients who lost their chance for umbilical cord blood isolation and preservation. As these cells became useful for tissue engineering and cell therapy, proper mode of their preservation also became important. The most important points in the cryopreservation and recovery procedure are: growth phase of harvested cells, number of cells, the proper cryopreservative concentration and serum concentration. The cryopreservation process includes the following general components: harvesting of the cells, addition of cryopreservative, the freezing procedure, the thawing procedure and assessment of the viability prior to transplantation. There is no single and perfect cryopreservation method. Further investigations should be regarding capability of DPSCs and their differentiated cells to recover and restart proliferation, differentiation and new tissue production for therapeutic use after cryopreservation
Eritropoetin u procjeni ishoda lijeÄenja kod bolesnika s politraumom
Polytrauma is a term describing patients with injuries involving multiple body regions that compromises function of the body and/or organ involved. The aim of the study was to evaluate the potential role of erythropoietin in predicting poorer outcome in trauma patients. This prospective study included 86 patients admitted to the Emergency Center of Serbia due to polytrauma assigned according to Injury Severity Score (ISS). The patients were further evaluated using the Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores and erythropoietin levels. There was a significant difference among erythropoietin levels at admission, after 48 and 72 hours, and on day 7 of hospital stay, with significantly higher levels in patients with ISS values 49-75. Based on the results, ROC curves were used to identify cut-off levels to predict ISS score with critical clinical course. It was concluded that erythropoietin could be a good marker of injury severity. Further research has to be performed to determine the cut-off values of erythropoietin that are significant for injury severity.Politrauma je termin koji opisuje bolesnike s povredama koje ukljuÄuju viÅ”e dijelova tijela i koje ugrožavaju funkciju Ātijela i/ili organa. Cilj studije je bio procijeniti potencijalnu ulogu eritropoetina u predviÄanju loÅ”eg ishoda kod bolesnika s poliĀtraumom. Ova prospektivna studija obuhvatila je 86 bolesnika koji su primljeni u Urgentni centar Srbije zbog politraume dijagnosticirane prema rezultatu težine povreda (Injury Severity Score, ISS). Bolesnici su dalje procijenjeni pomoÄu rezultata Akutnog fizioloÅ”kog bodovnog sustava i bodovnog sustava kroniÄne procjene zdravlja II. te procjene insuficijencije organa i razine eritropoetina. Postojala je znaÄajna razlika izmeÄu razine eritropoetina kod prijma, poslije 48 i 72 sata te sedmog dana boravka u bolnici, sa znatno viÅ”im razinama kod bolesnika s vrijednostima ISS 49-75. Na osnovi rezultata krivulje ROC su primijenjene za identifikaciju graniÄnih vrijednosti kako bi se predvidio rezultat ISS s kritiÄnim kliniÄkim tijekom. ZakljuÄeno je da eritropoetin može biti dobar pokazatelj ozbiljnosti povreda. Potrebno je daljnje istraživanje za odreÄivanje graniÄnih vrijednosti eritropoetina koje su znaÄajne za ozbiljnost povreda
DNA binding properties, histidine interaction and cytotoxicity studies of water soluble ruthenium(II) terpyridine complexes
In this study, two representatives of previously synthesized ruthenium(II) terpyridine complexes, i.e., [Ru(Cl-tpy)(en)Cl][Cl] (1) and [Ru(Cl-tpy)(dach)Cl][Cl] (2), were chosen and a detailed study of the kinetic parameters of their reactivity toward L-histidine (L-His), using the UV-Vis and 1H NMR techniques, was developed. The inner molecular rearrangement from N3-coordinated L-His to the N1 bound isomer, observable in the NMR data, was corroborated by DFT calculations favoring N1 coordination by nearly 4 kcal molā1. These two ruthenium(II) terpyridine complexes were investigated for their interactions with DNA employing UV-Vis spectroscopy, DNA viscosity measurements and fluorescence quenching measurements. The high binding constants obtained in the DNA binding studies (Kb = 104ā105 Mā1) suggest a strong binding of the complexes to calf thymus (CT) DNA. Competitive studies with ethidium bromide (EB) showed that the complexes can displace DNA-bound EB, suggesting strong competition with EB (Ksv = 1.5ā2.5 Ć 104 Mā1). In fact, the results indicate that these complexes can bind to DNA covalently and non-covalently. In order to gain insight of the behavior of a neutral compound, besides the four previously synthesized cationic complexes [Ru(Cl-tpy)(en)Cl][Cl] (1), [Ru(Cl-tpy)(dach)Cl][Cl] (2), [Ru(Cl-tpy)(bpy)Cl][Cl] (3) and [Ru(tpy)Cl3] (P2), a new complex, [Ru(Cl-tpy)(pic)Cl] (4), was used in the biological studies. Their cytotoxicity was investigated against three different tumor cell lines, i.e., A549 (human lung carcinoma cell line), HCT116 (human colon carcinoma cell line), and CT26 (mouse colon carcinoma cell line), by the MTT assay. Complexes 1 and 2 showed higher activity than complexes 3, 4 and P2 against all the selected cell lines. The results on in vitro anticancer activity confirmed that only compounds that hydrolyze the monodentate ligand at a reasonable rate show moderate activity, provided that the chelate ligand is a hydrogen bond donor