106 research outputs found
Ugt1a1 (ta)(n) promoter genotype: diagnostic and population pharmacogenetic marker in Serbia
The UGT1A1 enzyme is involved in the metabolism of bilirubin and numerous medications. Unconjugated hyper-bilirubinemia, commonly presented as Gilbert syndrome (GS), is a result of decreased activity of the UGT1A1 enzyme, variable number of TA repeats in the promoter of the UGT1A1 gene affects enzyme activity. Seven and eight TA repeats cause a decrease of UGT1A1 activity and risk GS alleles, while six TA repeats contribute to normal UGT I Al activity and non-risk GS allele. Also, the UGT1A1 (TA)(n) promoter genotype is recognized as a clinically relevant phannacogenetic marker. The aim of this study was to access diagnostic value of UGTIAI (TA) n promoter genotyping in pediatric GS patients. Correlation of the UGT1A1(TA)(n) genotypes and level of unconjugated bilirubin at diagnosis and after hypocaloric and phenobarbitone tests in these patients was analyzed. Another aim of the study was to assess phannacogenetic potential ofUGT1A1 (TA)(n) variants in Serbia. Fifty-one pediatric GS patients and 100 healthy individuals were genotyped using different methodologies, polymerise chain reaction (PCR) followed by acrylamide electrophoresis, fragment length analysis and/or DNA sequencing. Concordance of the UGT1A1 (TA)(n) promoter risk GS genotypes with GS was found in 80.0% of patients. Therefore, UGT1A1 (TA)(n) promoter genotyping is not a reliable genetic test for GS, but it is useful for differential diagnosis of diseases associated with hyperbilirubinemia. Level of bilimbin in pediatric GS patients at diagnosis wasUGT1A1 (TA)(n) promoter genotype-dependent. We found that the frequency of phannacogenetic relevant UGT1A1 (TA)(n) promoter genotypes was 63.0%, pointing out that UGT1A1 (TA)(n) promoter genoty ping could be recommended for preemptive pharmacogendic testing in Serbia
Orientational Ordering in Spatially Disordered Dipolar Systems
This letter addresses basic questions concerning ferroelectric order in
positionally disordered dipolar materials. Three models distinguished by dipole
vectors which have one, two or three components are studied by computer
simulation. Randomly frozen and dynamically disordered media are considered. It
is shown that ferroelectric order is possible in spatially random systems, but
that its existence is very sensitive to the dipole vector dimensionality and
the motion of the medium. A physical analysis of our results provides
significant insight into the nature of ferroelectric transitions.Comment: 4 pages twocolumn LATEX style. 4 POSTSCRIPT figures available from
[email protected]
Polyphenol rich extracts of Geranium L. species as potential natural antioxidant and antimicrobial agents
OBJECTIVE: Plants and plant extracts are of great scientific interest due to the
chemical diversity and pharmacological properties of present bioactive molecules. The Geranium L. species are widely used in ethnomedicine. In the current study, the total phenolic and
tannin content, antioxidant and antimicrobial
activity of methanol extracts of eight Geranium
species were investigated.
MATERIALS AND METHODS: The total phenolic and tannin content were determined by the
FC method. Antioxidant capacity was evaluated
in FRAP, DPPH, and biochemical assays, while
antimicrobial activity was examined using the
broth microdilution method.
RESULTS: The high total phenolic (170.64-
636.32 mg GAE/g dry extract) and tannin content (37.80-414.02 mg GAE/g DE), along with significant total antioxidant (FRAP values 1.13-8.80
mmol Fe2+/g) and DPPH radical scavenging activity (SC50 values 4.24-34.52 µg/mL) were observed. The prominent antioxidant capacity was
confirmed in biochemical assays (OS values -1.47
– -13.02). The extracts exhibited significant antimicrobial activity against ATTC strains (MICs
dominantly in the range of 12.5-200 µg/mL) as
well as against clinical isolates of E. coli (MICs
mostly 50 and 100 µg/mL). The pronounced antioxidant and antimicrobial activity can be due to
the high phenolic content, particularly due to the
presence of hydrolyzable tannins.
CONCLUSIONS: Based on the high content of
polyphenols, pronounced antioxidant and antimicrobial activities, the examined extracts are
promising natural antioxidant and antimicrobial
agents with the potential medicinal purpose and
use as a functional food
Quantum corrections to the ground state energy of a trapped Bose-Einstein condensate: A diffusion Monte Carlo calculation
The diffusion Monte Carlo method is applied to describe a trapped atomic
Bose-Einstein condensate at zero temperature, fully quantum mechanically and
nonperturbatively. For low densities, [n(0): peak
density, a: s-wave scattering length], our calculations confirm that the exact
ground state energy for a sum of two-body interactions depends on only the
atomic physics parameter a, and no other details of the two-body model
potential. Corrections to the mean-field Gross-Pitaevskii energy range from
being essentially negligible to about 20% for N=2-50 particles in the trap with
positive s-wave scattering length a=100-10000 a.u.. Our numerical calculations
confirm that inclusion of an additional effective potential term in the
mean-field equation, which accounts for quantum fluctuations [see e.g. E.
Braaten and A. Nieto, Phys. Rev. B 56}, 14745 (1997)], leads to a greatly
improved description of trapped Bose gases.Comment: 7 pages, 4 figure
Step bunching with both directions of the current: Vicinal W(110) surfaces versus atomistic scale model
We report for the first time the observation of bunching of monoatomic steps
on vicinal W(110) surfaces induced by step up or step down currents across the
steps. Measurements reveal that the size scaling exponent {\gamma}, connecting
the maximal slope of a bunch with its height, differs depending on the current
direction. We provide a numerical perspective by using an atomistic scale model
with a conserved surface flux to mimic experimental conditions, and also for
the first time show that there is an interval of parameters in which the
vicinal surface is unstable against step bunching for both directions of the
adatom drift.Comment: 17 pages, 10 figure
Dynamic correlations in an ordered c(22) lattice gas
We obtain the dynamic correlation function of two-dimensional lattice gas
with nearest-neighbor repulsion in ordered c(22) phase
(antiferromagnetic ordering) under the condition of low concentration of
structural defects. It is shown that displacements of defects of the ordered
state are responsible for the particle number fluctuations in the probe area.
The corresponding set of kinetic equations is derived and solved in linear
approximation on the defect concentration. Three types of strongly correlated
complex jumps are considered and their contribution to fluctuations is
analysed. These are jumps of excess particles, vacancies and flip-flop jumps.
The kinetic approach is more general than the one based on diffusion-like
equations used in our previous papers. Thus, it becomes possible to adequately
describe correlations of fluctuations at small times, where our previous theory
fails to give correct results. Our new analytical results for fluctuations of
particle number in the probe area agree well with those obtained by Monte Carlo
simulations.Comment: 10 pages, 7 figure
Force-velocity relation and density profiles for biased diffusion in an adsorbed monolayer
In this paper, which completes our earlier short publication [Phys. Rev.
Lett. 84, 511 (2000)], we study dynamics of a hard-core tracer particle (TP)
performing a biased random walk in an adsorbed monolayer, composed of mobile
hard-core particles undergoing continuous exchanges with a vapor phase. In
terms of an approximate approach, based on the decoupling of the third-order
correlation functions, we obtain the density profiles of the monolayer
particles around the TP and derive the force-velocity relation, determining the
TP terminal velocity, V_{tr}, as the function of the magnitude of external bias
and other system's parameters. Asymptotic forms of the monolayer particles
density profiles at large separations from the TP, and behavior of V_{tr} in
the limit of small external bias are found explicitly.Comment: Latex, 31 pages, 3 figure
General energy bounds for systems of bosons with soft cores
We study a bound system of N identical bosons interacting by model pair
potentials of the form V(r) = A sgn(p)r^p + B/r^2, A > 0, B >= 0. By using a
variational trial function and the `equivalent 2-body method', we find explicit
upper and lower bound formulas for the N-particle ground-state energy in
arbitrary spatial dimensions d > 2 for the two cases p = 2 and p = -1. It is
demonstrated that the upper bound can be systematically improved with the aid
of a special large-N limit in collective field theory
The scandium effect in multicomponent alloys
Despite its excellent elemental properties, lightweight nature and good alloying potential, scandium has received relatively little attention in the manufacturing community. The abundance of scandium in the Earth's crust is quite high. It is more abundant than silver, cobalt, lead and tin. But, because scandium is so well dispersed in the lithosphere, it is notoriously difficult to extract in commercial quantities – hence low market availability and high cost. Scandium metallurgy is still a largely unexplored field – but progress is being made. This review aims to summarise advances in scandium metallurgical research over the last decade. The use of scandium as a conventional minor addition to alloys, largely in structural applications, is described. Also, more futuristic functional applications are discussed where details of crystal structures and peculiar symmetries are often of major importance. This review also includes data obtained from more obscure sources (especially Russian publications) which are much less accessible to the wider community. It is clear that more fundamental research is required to elevate the status of scandium from a laboratory-based curiosity to a mainstream alloying element. This is largely uncharted territory. There is much to be discovered
Sex Bias in Pathogenesis of Autoimmune Neuroinflammation: Relevance for Dimethyl Fumarate Immunomodulatory/Anti-oxidant Action
In the present study, upon showing sexual dimorphism in dimethyl fumarate (DMF) efficacy to moderate the clinical severity of experimental autoimmune encephalomyelitis (EAE) in Dark Agouti rats, cellular and molecular substrate of this dimorphism was explored. In rats of both sexes, DMF administration from the day of immunization attenuated EAE severity, but this effect was more prominent in males leading to loss of the sexual dimorphism observed in vehicle-administered controls. Consistently, in male rats, DMF was more efficient in diminishing the number of CD4+ T lymphocytes infiltrating spinal cord (SC) and their reactivation, the number of IL-17+ T lymphocytes and particularly cellularity of their highly pathogenic IFN-gamma+GM-CSF+IL-17+ subset. This was linked with changes in SC CD11b+CD45+TCR alpha beta- microglia/proinflammatory monocyte progeny, substantiated in a more prominent increase in the frequency of anti-inflammatory phygocyting CD163+ cells and the cells expressing high surface levels of immunoregulatory CD83 molecule (associated with apoptotic cells phagocytosis and implicated in downregulation of CD4+ T lymphocyte reactivation) among CD11b+CD45+TCR alpha beta- cells in male rat SC. These changes were associated with greater increase in the nuclear factor (erythroid-derived 2)-like 2 expression in male rats administered with DMF. In accordance with the previous findings, DMF diminished reactive nitrogen and oxygen species generation and consistently, SC level of advanced oxidation protein products, to the greater extent in male rats. Overall, our study indicates sex-specificity in the sensitivity of DMF cellular and molecular targets and encourages sex-based clinical research to define significance of sex for action of therapeutic agents moderating autoimmune neuroinflammation-/oxidative stress-related nervous tissue damage
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