Abstract: The bioassay-guided isolation and purification of an
ethyl acetate extract of Aspergillus terreus MC751 led to the
characterization of butyrolactone I as an antidiabetic and antioxidant.
The antidiabetic activity of butyrolactone I was evaluated by α-
glucosidase and α-amylase inhibition assays. Butyrolactone I
demonstrated significant concentration-dependent, mixed-type
inhibitory activity against yeast α-glucosidase with an IC50 of 54μM.
However, the compound exhibited less activity against rat intestinal
α-glucosidase and α-amylase. This is the first report on α-glucosidase
inhibitory activity of butyrolactone I. The antioxidative activity of
butyrolactone I was evaluated based on scavenging effects on 1,1-
diphenyl-2-picrylhydrazyl (DPPH) (IC50 =51 μM) and hydrogen
peroxide (IC50= 141 μM) radicals as well as a reducing power assay.
The results suggest that butyrolactone I is a promising antidiabetic as
well as antioxidant and should be considered for clinical trials.
Abstract: Influence of octane and benzene on plant cell
ultrastructure and enzymes of basic metabolism, such as nitrogen
assimilation and energy generation have been studied. Different
plants: perennial ryegrass (Lolium perenne) and alfalfa (Medicago
sativa); crops- maize (Zea mays L.) and bean (Phaseolus vulgaris);
shrubs – privet (Ligustrum sempervirens) and trifoliate orange
(Poncirus trifoliate); trees - poplar (Populus deltoides) and white
mulberry (Morus alba L.) were exposed to hydrocarbons of different
concentrations (1, 10 and 100 mM). Destructive changes in bean and
maize leaves cells ultrastructure under the influence of benzene
vapour were revealed at the level of photosynthetic and energy
generation subcellular organells. Different deviations at the level of
subcellular organelles structure and distribution were observed in
alfalfa and ryegrass root cells under the influence of benzene and
octane, absorbed through roots. The level of destructive changes is
concentration dependent. Benzene at low 1 and 10 mM concentration
caused the increase in glutamate dehydrogenase (GDH) activity in
maize roots and leaves and in poplar and mulberry shoots, though to
higher extent in case of lower, 1mM concentration. The induction
was more intensive in plant roots. The highest tested 100mM
concentration of benzene was inhibitory to the enzyme in all plants.
Octane caused induction of GDH in all grassy plants at all tested
concentrations; however the rate of induction decreased parallel to
increase of the hydrocarbon concentration. Octane at concentration 1
mM caused induction of GDH in privet, trifoliate and white mulberry
shoots. The highest, 100mM octane was characterized by inhibitory
effect to GDH activity in all plants. Octane had inductive effect on
malate dehydrogenase in almost all plants and tested concentrations,
indicating the intensification of Trycarboxylic Acid Cycle.
The data could be suggested for elaboration of criteria for plant
selection for phytoremediation of oil hydrocarbons contaminated
soils.
Abstract: β-Glucosidase is an important enzyme for production
of ethanol from lignocellulose. With hydrolytic activity on
cellooligosaccharides, especially cellobiose, β-glucosidase removes
product inhibitory effect on cellulases and forms fermentable sugars.
In this study, β-glucosidase encoding gene (BGL1) from traditional
starter yeast Saccharomycosis fibuligera BMQ908 was cloned and
expressed in Pichia pastoris. BGL1 of S. fibuligera BMQ 908 shared
98% nucleotide homology with the closest GenBank sequence
(M22475) but identity in amino-acid sequences of catalytic domains.
Recombinant plasmid pPICZαA/BGL1 containing the sequence
encoding BGL1 mature protein and α-factor secretion signal was
constructed and transformed into methylotrophic yeast P. pastoris by
electroporation. The recombinant strain produced single extracellular
protein with molecular weight of 120 kDa and cellobiase activity of
60 IU/ml. The optimum pH of the recombinant β-glucosidase was 5.0
and the optimum temperature was 50°C.
Abstract: Proteins levels produced by bacteria may be increased
in stressful surroundings, such as in the presence of antibiotics. It
appears that many antimicrobial agents or antibiotics, when used at
low concentrations, have in common the ability to activate or repress
gene transcription, which is distinct from their inhibitory effect.
There have been comparatively few studies on the potential of
antibiotics or natural compounds in nature as a specific chemical
signal that can trigger a variety of biological functions. Therefore,
this study was focusing on the effect of essential oils from
Cymbopogon flexuosus and C. nardus in regulating proteins
production by Bacillus subtilis ATCC 21332. The Minimum
Inhibition Concentrations (MICs) of both essential oils on B. subtilis
were determined by using microdilution assay, resulting 0.2% and
1.56% for each C. flexuosus and C. nardus subsequently. The
bacteria were further exposed to each essential oils at concentration
of 0.01XMIC for 2 days. The proteins were then isolated and
analyzed by sodium dodecyl sulfate polyacrylamide gel
electrophoresis (SDS-PAGE). Protein profile showed that a band
with approximate size of 250 kD was appeared for the treated
bacteria with essential oils. Thus, Bacillus subtilis ATCC 21332 in
stressful condition with the presence of essential oils at low
concentration could induce the protein production.
Abstract: By using the method of coincidence degree theory and constructing suitable Lyapunov functional, several sufficient conditions are established for the existence and global exponential stability of anti-periodic solutions for Cohen-Grossberg shunting inhibitory neural networks with delays. An example is given to illustrate our feasible results.
Abstract: A series of 1-(1H-benzimidazol-2-yl)-3-(substituted phenyl)-2-propen-1-one were allowed to react with hydrazine hydrate and phenyl hydrazine in submitted reactions to get pyrazoline and phenyl pyrazoline derivatives. All the compounds entered for screening at the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) for their in vitro antibacterial activity against Mycobacterium tuberculosis H37Rv strain (ATCC 27294) using Microplate Alamar Blue Assay (MABA) susceptibility test. The results expressed as MIC (minimum inhibitory concentration) in μg/mL. Among the fifteen compounds, eight compounds were found to have MIC values less than 10 μg/mL. These were subjected for cytotoxicity assay in VERO cells to determine CC50 (cytotoxic concentration 50%) values and finally SI (Selectivity Index) were calculated. Compound (XV) 2-[5-(4- fluorophenyl)-1-phenyl-4,5-dihydro-1H-3-pyrazolyl]-1Hbenzimidazole was considered the best candidate of the series that could be a good starting point to develop new lead compounds in the fight against tuberculosis.
Abstract: In this paper, a mathematical model of human immunodeficiency
virus (HIV) is utilized and an optimization problem is
proposed, with the final goal of implementing an optimal 900-day
structured treatment interruption (STI) protocol. Two type of commonly
used drugs in highly active antiretroviral therapy (HAART),
reverse transcriptase inhibitors (RTI) and protease inhibitors (PI), are
considered. In order to solving the proposed optimization problem an
adaptive memetic algorithm with population management (AMAPM)
is proposed. The AMAPM uses a distance measure to control the
diversity of population in genotype space and thus preventing the
stagnation and premature convergence. Moreover, the AMAPM uses
diversity parameter in phenotype space to dynamically set the population
size and the number of crossovers during the search process.
Three crossover operators diversify the population, simultaneously.
The progresses of crossover operators are utilized to set the number
of each crossover per generation. In order to escaping the local optima
and introducing the new search directions toward the global optima,
two local searchers assist the evolutionary process. In contrast to
traditional memetic algorithms, the activation of these local searchers
is not random and depends on both the diversity parameters in
genotype space and phenotype space. The capability of AMAPM in
finding optimal solutions compared with three popular metaheurestics
is introduced.
Abstract: An experimental study of anaerobic treatment was performed by hybrid upflow anaerobic sludge blanket (HUASB) reactor to treat produced water (PW) of an onshore crude oil terminal (COD: 1597 mg/L, NH3-N: 14.7 mg/L, phenol: 13.8 mg/L, BOD5: 862 mg/L, sodium: 6240 mg/L and chloride 9530 mg/L). The produced water with high salinity and other toxic substances will inhibit the methanogens performance if there is no adaptation on biomass before anaerobic digestion. COD removal from produced water was investigated at five different dilutions of produced water and tap water (TW) without any nutrient addition and pre-treatment. The dilution ratios were 1PW:4TW, 2PW:3TW, 3PW:2TW, 4PW:1TW and 5PW:0TW. The reactor was evaluated at mesophilic operating condition (35 ± 2 °C) at 5 days of HRT for 250 days continuous feed. The average COD removals for 1PW:4TW, 2PW:3TW, 3PW:2TW, 4PW:1TW and 5PW:0TW were found to be approximately 76.1%, 73.8%, 70.3%, 46.3% and 61.82% respectively, with final average effluent COD of 123.7 mg/L, 240 mg/L, 294 mg/L, 589 mg/L and 738 mg/L, respectively.
Abstract: A new, simple and highly sensitive kinetic
spectrophotometric method was developed for the determination of
trace amounts of Ru(III) in the range of 0.06-20 ng/ml .The method
is based on the inhibitory effect of ruthenium(III) on the oxidation of
Rhodamine B by bromate in acidic and micellar medium. The
reaction was monitored spectrophotometrically by measuring the
decreasing in absorbance of Rhodamine B at 554 nm with a fixedtime
method..The limit of detection is 0.04 ng/ml Ru(III).The relative
standard deviation of 5 and 10 ng/ml Ru(III) was 2.3 and 2.7 %,
respectively. The method was applied to the determination of
ruthenium in real water samples
Abstract: Biofuels, like biobutanol, have been recognized for
being renewable and sustainable fuels which can be produced from
lignocellulosic biomass. To convert lignocellulosic biomass to
biofuel, pretreatment process is an important step to remove
hemicelluloses and lignin to improve enzymatic hydrolysis. Dilute
acid pretreatment has been successful developed for pretreatment of
corncobs and the optimum conditions of dilute sulfuric and
phosphoric acid pretreatment were obtained at 120 °C for 5 min with
15:1 liquid to solid ratio and 140 °C for 10 min with 10:1 liquid to
solid ratio, respectively. The result shows that both of acid
pretreatments gave the content of total sugar approximately 34–35
g/l. In case of inhibitor content (furfural), phosphoric acid
pretreatment gives higher than sulfuric acid pretreatment.
Characterizations of corncobs after pretreatment indicate that both of
acid pretreatments can improve enzymatic accessibility and the better
results present in corncobs pretreated with sulfuric acid in term of
surface area, crystallinity, and composition analysis.
Abstract: Leonotisleonurus a shrub indigenous to Southern
Africa is widely used in traditional medicine to treat a variety of
conditions ranging from skin diseases and cough to epileptic fits and
‘heart problems’. Studies on the aqueous extract of the leaves have
indicated cycloxegenase enzyme inhibitory activity and an
antihypertensive effect.
Five methanol leaf extract fractions (MLEa - MLEe) of L.
leonurus were tested on anaesthetized normotensive male Wistar rats
(AWR) and isolated perfused working rat hearts (IWH). Fraction
MLEc (0.01mg/kg – 0.05mg/kg) induced significant increases in BP
and HR in AWR and positive chronotropic and inotropic effects in
IWH (1.0mg/ml – 5.0mg/ml). Pre-administration of atenolol
(2.0mg/kg) and prazosin (60μg/kg) significantly inhibited MLEc
effect on HR and MAP respectively in vivo, while atenolol
(7.0mg/ml) pre-perfusion significantly inhibited MLEc effect in vitro.
The hypertensive effect of MLEc is probably via β1agonism.
Results also indicate the presence of multiple cardioactive
compounds in L. leonurus.
Abstract: Food borne illnesses have been reported to be a global
health challenge. Annual incidences of food–related diseases involve
76 million cases, of which only 14 million can be traced to known
pathogens. Poor hygienic practices have contributed greatly to this. It
has been reported that in the year 2000 about 2.1 million people died
from diarrheal diseases, hence, there is a need to ensure food safety at
all level. This study focused on the sterility examination and
inhibitory effect of honey samples on selected gram negative and
gram positive food borne pathogen from South West Nigeria. The
laboratory examinations revealed the presence of some bacterial and
fungal contaminations of honey samples and that inhibitory activity
of the honey sample was more pronounced on the gram negative
bacteria than the gram positive bacterial isolates. Antibiotic
sensitivity test conducted on the different bacterial isolates also
showed that honey was able to inhibit the proliferation of the tested
bacteria than the employed antibiotics.
Abstract: In this paper, based on the estimation of the Cauchy matrix of linear impulsive differential equations, by using Banach fixed point theorem and Gronwall-Bellman-s inequality, some sufficient conditions are obtained for the existence and exponential stability of almost periodic solution for Cohen-Grossberg shunting inhibitory cellular neural networks (SICNNs) with continuously distributed delays and impulses. An example is given to illustrate the main results.
Abstract: The methanolic extracts from seeds of tamarind
(Tamarindus indica) was prepared by Soxhlet apparatus extraction
and evaluated for total phenolic content by Folin-Ciocalteu method.
Then, methanolic extract was screened biological activities (In vitro)
for anti-melanogenic activity by tyrosinase inhibition test, antiinflammation
activity by cyclooxygenase 1 (COX-1) and
cyclooxygenase 2 (COX-2) inhibition test, and cytotoxic screening
test with Vero cells. The results showed that total phenolic content,
which contained in extract, was contained 27.72 mg of gallic acid
equivalent per g of dry weight. The ability to inhibit tyrosinase
enzyme, which exerted by Tamarind seed extracts (1 mg/ml) was
52.13 ± 0.42 %. The extract was not possessed inhibitory effect to
COX-1 and COX-2 enzymes and cytotoxic effect to Vero cells. The
finding is concludes that tested seed extract was possessed
antimelanogenic activity with non-toxic effects. However, there was
not exhibited anti-inflammatory activity. Further studies include the
use of advance biological models to confirm this biological activity,
as well as, the isolation and characterization of the purified
compounds that it was contained.
Abstract: Mammals are known to use Interaural Intensity Difference (IID) to determine azimuthal position of high frequency sounds. In the Lateral Superior Olive (LSO) neurons have firing behaviours which vary systematicaly with IID. Those neurons receive excitatory inputs from the ipsilateral ear and inhibitory inputs from the contralateral one. The IID sensitivity of a LSO neuron is thought to be due to delay differences between both ears, delays due to different synaptic delays and to intensity-dependent delays. In this paper we model the auditory pathway until the LSO. Inputs to LSO neurons are at first numerous and differ in their relative delays. Spike Timing-Dependent Plasticity is then used to prune those connections. We compare the pruned neuron responses with physiological data and analyse the relationship between IID-s of teacher stimuli and IID sensitivities of trained LSO neurons.
Abstract: Bone growth factors, such as Bone Morphogenic
Protein-2 (BMP-2) have been approved by the FDA to replace grafting for some surgical interventions, but the high dose requirement limits its use in patients. Noggin, an extracellular protein, blocks the effect of BMP-2 by binding to BMP. Preventing
the BMP-2/noggin interaction will help increase the free
concentration of BMP-2 and therefore should enhance its efficacy to
induce bone formation. The work presented here involves
computational design of novel small molecule inhibitory agents of BMP-2/noggin interaction, based on our current understanding of
BMP-2, and its known putative ligands (receptors and antagonists). A
successful acquisition of such an inhibitory agent of BMP-2/noggin interaction would allow clinicians to reduce the dose required of
BMP-2 protein in clinical applications to promote osteogenesis. The
available crystal structures of the BMPs, its receptors, and the binding partner noggin were analyzed to identify the critical residues
involved in their interaction. In presenting this study, LUDI de novo design method was utilized to perform virtual screening of a large
number of compounds from a commercially available library against the binding sites of noggin to identify the lead chemical compounds
that could potentially block BMP-noggin interaction with a high specificity.
Abstract: Microorganisms isolated from water and soil of
Kazakhstan to identify potential high-effective producers of the
arachidonic acid, exhibiting a wide range of physiological activity
and having practical applications were screened. Based on the results
of two independent tests (the test on the sensitivity of the growth
processes of microorganisms to acetylsalicylic acid - an irreversible
inhibitor of PGH-synthase involved in the metabolism of arachidonic
acid and its derivatives, the test for inhibition of peroxidase activity
of membrane-bounding fraction of PGH - synthase by acetylsalicylic
acid) were selected microbial cultures which are potential highproducer
of arachidonic acid. They are characterized by a stable
strong growth in the laboratory conditions. Identification of
microorganism cultures based on morphological, physiological,
biochemical and molecular genetic characteristics was performed.
Abstract: Two indica varieties, IR36 and ‘Suweon 258’ (“S”)
are middle-heading in southern Japan. 36U, also middle-heading, is
an isogenic line of IR36 carrying Ur1 (Undulate rachis-1) gene.
However, late-heading plants segregated in the F2 population from
the F1 of S × 36U, and so did in the following generations. The
concerning lateness gene is designated as Ex. From the F8 generation,
isogenic-line pair of early-heading and late-heading lines, denoted by
“E” (ex/ex) and “L” (Ex/Ex), were developed. Genetic analyses of
heading time were conducted, using F1s and F2s among L, E, S and
36U. The following inferences were drawn from the experimental
results: 1) L, and both of E and 36U harbor Ex and ex, respectively;
2) Besides Ex, S harbors an inhibitor gene to it, i.e. I-Ex which is a
novel finding of the present study. 3) Ex is a dominant allele at the
E1 locus.
Abstract: Chitosan is a biopolymer composed of glucosamine
and N-acetyl glucosamine. Solubility and viscosity pose problems in
some applications. These problems can be overcome with unique
modifications. In this study, firstly, chitosan was modified by caffeic
acid and thioglycolic acid, separately. Then, growing effects of these
modified polymers was observed in U937 cell line. Caffeic acid is a
phenolic compound and its modifications act carcinogenic inhibitors
in drugs. Thiolated chitosans are commonly being used for drugdelivery
systems in various routes, because of enhancing
mucoadhesiveness property. U937 cell line was used model cell for
leukaemia. Modifications were achieved by 1 – 15 % binding range.
Increasing binding ratios showed higher radical-scavenging activity
and reducing cell growth, in compared to native chitosan. Caffeic
acid modifications showed higher radical-scavenging activity than
thiolated chitosans at the same concentrations. Caffeic acid and
thioglycolic acid modifications inhibited growth of U937, effectively.
Abstract: Multidrug resistant organisms have been taunting the
medical world for the last few decades. Even with new antibiotics
developed, resistant strains have emerged soon after. With the
advancement of nanotechnology, we investigated colloidal silver
nanoparticles for its antimicrobial activity against Pseudomonas
aeruginosa. This organism is a multidrug resistant which contributes
to the high morbidity and mortality in immunocompromised patients.
Five multidrug resistant strains were used in this study. The
antimicrobial effect was studied using the disc diffusion and broth
dilution techniques. An inhibition zone of 11 mm was observed with
10 μg dose of the nanoparticles. The nanoparticles exhibited MIC of
50 μg/ml when added at the lag phase and the subinhibitory
concentration was measured as 100 μg/ml. The MIC50 value showed
to be 15 μg/ml. This study suggests that silver nanoparticles can be
further developed as an antimicrobial agent, hence decreasing the
burden of the multidrug resistance phenomena.