322 research outputs found
Effective target arrangement in a deterministic scale-free graph
We study the random walk problem on a deterministic scale-free network, in
the presence of a set of static, identical targets; due to the strong
inhomogeneity of the underlying structure the mean first-passage time (MFPT),
meant as a measure of transport efficiency, is expected to depend sensitively
on the position of targets. We consider several spatial arrangements for
targets and we calculate, mainly rigorously, the related MFPT, where the
average is taken over all possible starting points and over all possible paths.
For all the cases studied, the MFPT asymptotically scales like N^{theta}, being
N the volume of the substrate and theta ranging from (1 - log 2/log3), for
central target(s), to 1, for a single peripheral target.Comment: 8 pages, 5 figure
Staphylococcus aureus and autoimmune uveitis reactivation in childhood: a possible correlation?
The role of infectious agents in autoimmune diseases has been the subject of several studies and is still under investigation. Here a paediatric case series of autoimmune uveitis is reported. An exacerbation of the ocular inflammation occurred in concomitance with nasal colonisation by Staphylococcus aureus
Activity of a trinuclear platinum complex in human ovarian cancer cell lines sensitive and resistant to cisplatin: cytotoxicity and induction and gene-specific repair of DNA lesions
A collateral sensitivity or a very modest cross-resistance to BBR 3464 was found in 2 ovarian cancer cell lines with experimentally induced resistance to cisplatin. Loss of mismatch repair proteins (hMLH1, hPMS2) or overexpression of nucleotide excision repair proteins (ERCC1) was not detrimental for the cellular sensitivity to BBR 3464. Moreover, interesting differences in the kinetics of formation and removal of DNA lesions at the single-gene (N- ras) level were observed between BBR 3464 and CDDP. © 2001 Cancer Research Campaign www.bjcancer.co
The role of the vagus nerve during fetal development and its relationship with the environment
The autonomic nervous system (ANS) regulatory capacity begins before birth as
the sympathetic and parasympathetic activity contributes significantly to the
fetus' development. Several studies have shown how vagus nerve is involved in
many vital processes during fetal, perinatal and postnatal life: from the
regulation of inflammation through the anti-inflammatory cholinergic pathway,
which may affect the functioning of each organ, to the production of hormones
involved in bioenergetic metabolism. In addition, the vagus nerve has been
recognized as the primary afferent pathway capable of transmitting information
to the brain from every organ of the body. Therefore, this hypothesis paper
aims to review the development of ANS during fetal and perinatal life, focusing
particularly on the vagus nerve, to identify possible "critical windows" that
could impact its maturation. These "critical windows" could help clinicians
know when to monitor fetuses to effectively assess the developmental status of
both ANS and specifically the vagus nerve. In addition, this paper will focus
on which factors (i.e. fetal characteristics and behaviors, maternal lifestyle
and pathologies, placental health and dysfunction, labor, incubator conditions,
and drug exposure) may have an impact on the development of the vagus during
the above-mentioned "critical window" and how. This analysis could help
clinicians and stakeholders define precise guidelines for improving the
management of fetuses and newborns, particularly to reduce the potential
adverse environmental impacts on ANS development that may lead to persistent
long-term consequences. Since the development of ANS and the vagus influence
have been shown to be reflected in cardiac variability, this paper will rely in
particular on studies using fetal heart rate variability (fHRV) to monitor the
continued growth and health of both animal and human fetuses.Comment: Word count: 16,009 Tables: 1 Figures:
OVOL2 impairs RHO GTPase signaling to restrain mitosis and aggressiveness of Anaplastic Thyroid Cancer
Background: Anaplastic Thyroid Cancer (ATC) is an undifferentiated and aggressive tumor that often originates from well-Differentiated Thyroid Carcinoma (DTC) through a trans-differentiation process. Epithelial-to-Mesenchymal Transition (EMT) is recognized as one of the major players of this process. OVOL2 is a transcription factor (TF) that promotes epithelial differentiation and restrains EMT during embryonic development. OVOL2 loss in some types of cancers is linked to aggressiveness and poor prognosis. Here, we aim to clarify the unexplored role of OVOL2 in ATC. Methods: Gene expression analysis in thyroid cancer patients and cell lines showed that OVOL2 is mainly associated with epithelial features and its expression is deeply impaired in ATC. To assess OVOL2 function, we established an OVOL2-overexpression model in ATC cell lines and evaluated its effects by analyzing gene expression, proliferation, invasion and migration abilities, cell cycle, specific protein localization through immunofluorescence staining. RNA-seq profiling showed that OVOL2 controls a complex network of genes converging on cell cycle and mitosis regulation and Chromatin Immunoprecipitation identified new OVOL2 target genes. Results: Coherently with its reported function, OVOL2 re-expression restrained EMT and aggressiveness in ATC cells. Unexpectedly, we observed that it caused G2/M block, a consequent reduction in cell proliferation and an increase in cell death. This phenotype was associated to generalized abnormalities in the mitotic spindle structure and cytoskeletal organization. By RNA-seq experiments, we showed that many pathways related to cytoskeleton and migration, cell cycle and mitosis are profoundly affected by OVOL2 expression, in particular the RHO-GTPase pathway resulted as the most interesting. We demonstrated that RHO GTPase pathway is the central hub of OVOL2-mediated program in ATC and that OVOL2 transcriptionally inhibits RhoU and RhoJ. Silencing of RhoU recapitulated the OVOL2-driven phenotype pointing to this protein as a crucial target of OVOL2 in ATC. Conclusions: Collectively, these data describe the role of OVOL2 in ATC and uncover a novel function of this TF in inhibiting the RHO GTPase pathway interlacing its effects on EMT, cytoskeleton dynamics and mitosis
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