Background:
Developing a novel, efficient biomarker for detecting malignant tumors is
essential for the early diagnosis of cancers. Our aim was to assess the
diagnostic value of a potential plasma tumor marker, thioredoxin reductase
(TR), which is expressed in many types of malignant tumor, for the non-invasive
detection of cancers. Methods: The plasma activities of TR were measured in
1513 patients with common clinical diseases, 59 patients with benign tumors,
and 154 patients with cancers and 586 healthy controls. The area under the ROC
curve (AUC) of TR and logistic regression results of different groups were
compared by sensitivity, specificity and Youden’s index. Diagnostic cut-offs
and clinical reference intervals were established via ROC curve analysis.
Results: The logistic regression indicated that TR activity can discriminate
between cancers and benign tumors or other common diseases very well (p <
0.0001), with an area under the curve from the receiver-operator
characteristics between 0.91 and 0.96. The positive critical value was 2.51 and
the cancer critical value was 9.90. The diagnostic gray zone (2.51 - 9.90) may
be associated with benign tumors and some common clinical diseases.
Conclusions: As a novel potential marker of malignant tumors with quantitative
evaluation of proliferation, TR activity detection has an excellent diagnostic
potential for early-stage malignant tumors. Impact: The convenient, economical,
relatively non-invasive, and reproducible detection method of TR activity makes
it suitable for routine clinical practice.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
1-deoxy-D-xylulose
5-phosphate synthase (DXS) catalyzes the initial step of the 2-C-methyl-D-
erythritol 4-phosphate (MEP) pathway consisting in the condensation of
(hydroxiethyl)thiamin derived from pyruvate with D-glyceraldehyde 3-phosphate
(GAP) to yield 1-deoxy-D-xylulose 5-phosphate (DXP). The role of the conserved
residues H49, E370, D427 and H431 of E. coli DXS was examined by site-directed
mutagenesis and kinetic analysis of the purified recombinant enzyme mutants.
Mutants at position H49 showed a severe reduction in their specific activities
with a decrease of the kcat/KM ratio by two orders of magnitude lower than the
wild-type DXS. According to available structural data residue H49 is perfectly
positioned to abstract a proton from the donor substrate. Mutations in DXS E370
showed that this residue is also essential for catalytic activity.
Three-dimensional structure supports its involvement in cofactor deprotonation,
the first step in enzymatic thiamin catalysis. Results obtained with H431
mutant enzymes indicate that this residue plays a role contributing to
transition state stabilization. Finally, mutants at position D427 also showed a
severe specific activity decrease with a reduction of the kcat/KM ratio. A role
in binding the substrate and selecting the stereoisomer is proposed for D427.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
This
paper compares the irreversible and reversible rate equations from several
uni-uni kinetic mechanisms (Michaelis-Menten, Hill and Adair equations) and
bi-bi mechanisms (single- and double- displacement equations). In reversible
reactions, Haldane relationship is considered to be identical for all
mechanisms considered and reversible equations can be also obtained from this
rela- tionship. Some reversible reactions of the metabolism are also presented,
with their equilibrium constant.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
Clinical
data analysis is of fundamental importance, as classifications and detailed
characterizations of diseases help physicians decide suitable management for
patients, individually. In our study, we adopt diffusion maps to embed the data
into corresponding lower dimensional representation, which integrate the
information of potentially nonlinear progressions of the diseases. To deal with
nonuniformaity of the data, we also consider an alternative distance measure
based on the estimated local density. Performance of this modification is
assessed using artificially generated data. Another clinical dataset that
comprises metabolite concentrations measured with magnetic resonance
spectroscopy was also classified. The algorithm shows improved results compared
with conventional Euclidean distance measure.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
A
movie trailer is a common advertising tool in the entertainment industry.
Detection of a viewer’s brain responses to a movie trailer can help film
producers to tailor a more appealing trailer of a movie. In this study, we
acquired electroencephalographic (EEG) signals from subjects when they watched
movie trailers (labeled as Movie session), and compared with their resting
state session (labeled as Resting session) or when they watch nature scenes
(labeled as Nature session). We used Sample Entropy (SampEn) to analyze the EEG
signals between different sessions. Results showed that the complexity ratios
at Fp1, Fp2 and Fz channels derived from Movie session were significantly lower
than that in Resting state or when subjects watched Nature session (p <
0.001). Our results suggest that the brain status can affect the complexity of
their EEG. Further, the attraction of attention of a movie trailer can be
observed from the change of EEG.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
Conducting
science for practical ends implicates scientists, whether they wish it or not,
as agents in social-ecological systems, raising ethical, economic,
environmental, and political issues. Considering these issues helps scientists
to increase the relevance and sustainability of research outcomes. As we rise
to the worthy call to connect basic research with food production, scientists
have the opportunity to evaluate alternative food production paradigms and
consider how our research funds and efforts are best employed. In this
contribution, we review some of the problems produced by science conducted in
service of industrial agriculture and its associated economic growth paradigm.
We discuss whether the new concept of “ecological intensification” can rescue
the industrial agriculture/growth paradigm and present an emerging alternative
paradigm of decentralized, localized, biodiversity-promoting agriculture for a
steady-state economy. This “custom fit” agriculture engages constructively with
complex and highly localized ecosystems, and we draw from examples of published
work to demonstrate how ecologists can contribute by using approaches that
acknowledge local agricultural practices and draw on community participation
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
During
the past 50 years, the human population has more than doubled and global
agricultural production has similarly risen. However, the productive arable
area has increased by just 10%; thus the increased use of pesticides has been a
consequence of the demands of human population growth, and its impact has
reached global significance. Although we often know a pesticide′s mode of
action in the target species, we still largely do not understand the full
impact of unintended side effects on wildlife, particularly at higher levels of
biological organization: populations, communities, and ecosystems. In these
times of regional and global species declines, we are challenged with the task
of causally linking knowledge about the molecular actions of pesticides to
their possible interference with biological processes, in order to develop
reliable predictions about the consequences of pesticide use, and misuse, in a
rapidly changing world.
Website: https://www.arjonline.org/biosciences/american-research-journal-of-biosciences/
