253 research outputs found
Stance classification in rumours as a sequential task exploiting the tree structure of social media conversations
Rumour stance classification, the task that determines if each tweet in a collection discussing a rumour is supporting, denying, questioning or simply commenting on the rumour, has been attracting substantial interest. Here we introduce a novel approach that makes use of the sequence of transitions observed in tree-structured conversation threads in Twitter. The conversation threads are formed by harvesting users’ replies to one another, which results in a nested tree-like structure. Previous work addressing the stance classification task has treated each tweet as a separate unit. Here we analyse tweets by virtue of their position in a sequence and test two sequential classifiers, Linear-Chain CRF and Tree CRF, each of which makes different assumptions about the conversational structure. We experiment with eight Twitter datasets, collected during breaking news, and show that exploiting the sequential structure of Twitter conversations achieves significant improvements over the non-sequential methods. Our work is the first to model Twitter conversations as a tree structure in this manner, introducing a novel way of tackling NLP tasks on Twitter conversations
Free thyroxine and TSH interact with secreted protein acidic and rich in cysteine-like 1 in ischemic stroke
The role of the thyroid gland in ischemic stroke pathology is not well understood. As thyroid hormones modulate the extracellular matrix, we explored the possible link between them and secreted protein acidic and rich in cysteine like 1 (SC1) – one of the extracellular matrix molecules.
In the 81 patients with acute ischemic stroke, serum SC1 levels were much higher compared with 30 control subjects: 4.47 vs 2.43ng/mL (p<0.001). Serum levels of free thyroxine (fT4) were higher in stroke subjects compared to those of controls (p=0.03). In stroke patients, TSH concentration was lower than in the control group (p=0.03). SC1 levels positively correlated with fT4 levels (p=0.02) and negatively with TSH (p=0.03) in stroke patients.
Our results confirmed the association between thyroid hormones and SC1 – extracellular matrix protein
Discourse-aware rumour stance classification in social media using sequential classifiers
Rumour stance classification, defined as classifying the stance of specific social media posts into one of supporting, denying, querying or commenting on an earlier post, is becoming of increasing interest to researchers. While most previous work has focused on using individual tweets as classifier inputs, here we report on the performance of sequential classifiers that exploit the discourse features inherent in social media interactions or 'conversational threads'. Testing the effectiveness of four sequential classifiers -- Hawkes Processes, Linear-Chain Conditional Random Fields (Linear CRF), Tree-Structured Conditional Random Fields (Tree CRF) and Long Short Term Memory networks (LSTM) -- on eight datasets associated with breaking news stories, and looking at different types of local and contextual features, our work sheds new light on the development of accurate stance classifiers. We show that sequential classifiers that exploit the use of discourse properties in social media conversations while using only local features, outperform non-sequential classifiers. Furthermore, we show that LSTM using a reduced set of features can outperform the other sequential classifiers; this performance is consistent across datasets and across types of stances. To conclude, our work also analyses the different features under study, identifying those that best help characterise and distinguish between stances, such as supporting tweets being more likely to be accompanied by evidence than denying tweets. We also set forth a number of directions for future research
Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation
Intrauterine devices (IUDs) are used in mares to suppress oestrous behaviour, but the underlying mechanism is yet to be elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and, subsequently, prostaglandin (PG) release and luteolysis. However, inflammation may also be involved. Endometrial inflammatory markers in uterine lavage fluid were measured on Day 10 (EXP 1, n = 25) and Day 15 (EXP 2, n = 27) after ovulation in inseminated mares, non-pregnant or pregnant, and in mares in which a small plastic sphere had been inserted into the uterus 4 (EXP 1) or 3 days (EXP 2) after ovulation. Uterine lavage fluid samples were analysed for nitric oxide (NO), prostaglandin E2 (PGE2) (only EXP 1), prostaglandin F2α (PGF2α), inhibin A and cytokines, and blood samples for progesterone and oestradiol. On Day 10, the concentration of PGF2α was lower (p < 0.05) in the IUD group than in pregnant mares. The concentration of the modulatory cytokine IL-10 was significantly higher in the IUD group in comparison to non-pregnant mares, and inhibin A was significantly higher in IUD mares than in the pregnant counterparts on Day 15. The results suggest that the presence of IUD causes endometrial inflammation which is at a resolution stage on Day 15
Inflammatory Markers in Uterine Lavage Fluids of Pregnant, Non-Pregnant, and Intrauterine Device Implanted Mares on Days 10 and 15 Post Ovulation
Intrauterine devices (IUDs) are used in mares to suppress oestrous behaviour, but the underlying mechanism is yet to be elucidated. The presence of an embryo or an IUD prevents cyclooxygenase-2 (COX-2) and, subsequently, prostaglandin (PG) release and luteolysis. However, inflammation may also be involved. Endometrial inflammatory markers in uterine lavage fluid were measured on Day 10 (EXP 1, n = 25) and Day 15 (EXP 2, n = 27) after ovulation in inseminated mares, non-pregnant or pregnant, and in mares in which a small plastic sphere had been inserted into the uterus 4 (EXP 1) or 3 days (EXP 2) after ovulation. Uterine lavage fluid samples were analysed for nitric oxide (NO), prostaglandin E2 (PGE2) (only EXP 1), prostaglandin F2α (PGF2α), inhibin A and cytokines, and blood samples for progesterone and oestradiol. On Day 10, the concentration of PGF2α was lower (p < 0.05) in the IUD group than in pregnant mares. The concentration of the modulatory cytokine IL-10 was significantly higher in the IUD group in comparison to non-pregnant mares, and inhibin A was significantly higher in IUD mares than in the pregnant counterparts on Day 15. The results suggest that the presence of IUD causes endometrial inflammation which is at a resolution stage on Day 15
The inhibitory effect of noscapine on the in vitro cathepsin G-induced collagen expression in equine endometrium
Research Areas: Life Sciences & Biomedicine ; MicrobiologyABSTRACT - Cathepsin G (CAT) is a protease released by neutrophils when forming neutrophil extracellular traps that was already associated with inducing type I collagen (COL1) in equine endometrium
in vitro. Endometrosis is a fibrotic condition mainly characterized by COL1 deposition in the equine
endometrium. The objective was to evaluate if noscapine (an alkaloid for cough treatment with
anti-neoplastic and anti-fibrotic properties) would reduce COL1A2 transcription (evaluated by qPCR)
and COL1 protein relative abundance (evaluated by western blot) induced by CAT in equine endometrial explants from follicular and mid-luteal phases treated for 24 or 48 h. The explants treated with
CAT increased COL1 expression. Noscapine decreased COL1A2 transcription at both estrous cycle
phases, but COL1 relative protein only at the follicular phase, both induced by CAT. Additionally,
the noscapine anti-fibrotic action was found to be more effective in the follicular phase. The CAT
treatment caused more fibrosis at the longest period of treatment, while noscapine acted better at the
shortest time of treatment. Our results showed that noscapine could act as an anti-fibrotic drug in
equine endometrosis by inhibiting CAT in vitro. Noscapine offers a new promising therapeutic tool
for treating fibrosis as a single non-selective agent to be considered in the future.info:eu-repo/semantics/publishedVersio
The In vitro inhibitory effect of sivelestat on elastase induced collagen and metallopeptidase expression in equine endometrium
Research Areas: Agriculture ; Veterinary Sciences ; ZoologyAbstract: Neutrophil extracellular traps (NETs) fight endometritis, and elastase (ELA), a protease
found in NETs, might induce collagen type I (COL1) accumulation in equine endometrium.
Metallopeptidases (MMPs) are involved in extracellular matrix balance. The aim was to evaluate
the e ects of ELA and sivelestat (selective elastase inhibitor) on MMP-2 and MMP-9 expression and
gelatinolytic activity, as well as the potential inhibitory e ect of sivelestat on ELA-induced COL1 in
equine endometrium. Endometrial explants from follicular (FP) and mid-luteal (MLP) phases were
treated for 24 or 48 h with ELA, sivelestat, and their combination. Transcripts of COL1A2, MMP2, and
MMP9 were evaluated by qPCR; COL1 protein relative abundance by Western blot, and MMP-2 and
MMP-9 gelatinolytic activity by zymography. In response to ELA treatment, there was an increase in
MMP2 mRNA transcription (24 h) in active MMP-2 (48 h), both in FP, and in MMP9 transcripts in FP
(48 h) and MLP (24 h) (p < 0.05). Sivelestat inhibited ELA-induced COL1A2 transcripts in FP (24 h)
and MLP (24 h, 48 h) (p < 0.05). The sivelestat inhibitory e ect was detected in MMP9 transcripts
in FP at 48 h (p < 0.05), but proteases activity was unchanged. Thus, MMP-2 and MMP-9 might be
implicated in endometrium fibrotic response to ELA. In mare endometrium, sivelestat may decrease
ELA-induced COL1 deposition and hinder endometrosis development.info:eu-repo/semantics/publishedVersio
Myeloperoxidase inhibition decreases the expression of collagen and metallopeptidase in mare endometria under in vitro conditions
Research Areas: Agriculture ; Veterinary Sciences ; ZoologyABSTRACT - Neutrophils can originate neutrophil extracellular traps (NETs). Myeloperoxidase (MPO) is
a peroxidase found in NETs associated to equine endometrosis and can be inhibited by 4-aminobenzoic
acid hydrazide (ABAH). Metallopeptidases (MMPs) participate in extracellular matrix stability and
fibrosis development. The objectives of this in vitro work were to investigate, in explants of mare’s
endometrium, (i) the ABAH capacity to inhibit MPO-induced collagen type I (COL1) expression;
and (ii) the action of MPO and ABAH on the expression and gelatinolytic activity of MMP-2/-9.
Explants retrieved from the endometrium of mares in follicular or mid-luteal phases were treated
with MPO, ABAH, or their combination, for 24 or 48 h. The qPCR analysis measured the transcription
of COL1A2, MMP2, and MMP9. Western blot and zymography were performed to evaluate COL1
protein relative abundance and gelatinolytic activity of MMP-2/-9, respectively. Myeloperoxidase
elevated COL1 relative protein abundance at both treatment times in follicular phase (p < 0.05). The
capacity of ABAH to inhibit MPO-induced COL1 was detected in follicular phase at 48 h (p < 0.05).
The gelatinolytic activity of activated MMP-2 augmented in mid-luteal phase at 24 h after MPO
treatment, but it was reduced with MPO+ABAH treatment. The activity of MMP-9 active form
augmented in MPO-treated explants. However, this effect was inhibited by ABAH in the follicular
phase at 48 h (p < 0.05). By inhibiting the pro-fibrotic effects of MPO, it might be possible to reduce
the development of endometrosis. Metallopeptidase-2 might be involved in an acute response to
MPO in the mid-luteal phase, while MMP-9 might be implicated in a prolonged exposition to MPO
in the follicular phase.info:eu-repo/semantics/publishedVersio
Enzymes present in neutrophil extracellular traps may stimulate the fibrogenic PGF(2 alpha) pathway in the mare endometrium
Research Areas: AgricultureVeterinary SciencesEndometrosis is a fibrotic disease in mare endometrium whose pathological
mechanisms remain obscure. Prostaglandin (PG)F2α, despite modulating reproductive physiological
processes, may also provoke local pathological collagen deposition (fibrogenesis). Neutrophil extracellular traps (NETs) released during inflammation have been linked to fibrogenesis in several
tissues. We have previously shown that enzymes found in NETs increase in vitro collagen production
in mare endometrium. In this study, activation of PGF2α-pathway in equine endometrial explants
challenged in vitro by enzymes found in NETs is shown. Our results indicate that both endocrine
microenvironment (estrous cycle phase) and healthy or pathological conditions of endometrial tissues
play an important role in PGF2α-pathway activation. In the endometrium of the follicular phase,
we have observed both high production of PGF2α and/or PGF2α receptor gene transcription under
the action of enzymes found in NETs, both conditions associated with fibrogenesis in other tissues.
Nevertheless, transcription of the PGF2α receptor gene does not appear to be hormone-dependent,
albeit their levels seem to be dependent on endometrial category in the mid-luteal phase. This study
suggests that enzymes existing in NETs may instigate changes on PGF2α mediators, which may
become an additional mechanism of fibrogenesis in mare endometrium.info:eu-repo/semantics/publishedVersio
The inhibition of Cathepsin G on endometrial explants with endometrosis in the mare
Research Areas: Veterinary SciencesAlthough proteases found in neutrophil extracellular traps (NETs) have antimicrobial properties, they also stimulate collagen type 1 (COL1) production by the mare endometrium, contributing for the development of endometrosis. Cathepsin G (CAT), a protease present in NETs, is inhibited by specific inhibitors, such as cathepsin G inhibitor I (INH; beta-keto-phosphonic acid). Matrix metallopeptidases (MMPs) are proteases involved in the equilibrium of the extracellular matrix. The objective of this study was to investigate the effect of CAT and INH (a selective CAT inhibitor) on the expression of MMP-2 and MMP-9 and on gelatinolytic activity. In addition, the putative inhibitory effect of INH on CAT-induced COL1 production in mare endometrium was assessed. Endometrial explants retrieved from mares in follicular phase or midluteal phase were treated for 24 or 48 h with CAT, inhibitor alone, or both treatments. In explants, transcripts (quantitative polymerase chain reaction) of COL1A2, MMP2, and MMP9, as well as the relative abundance of COL1 protein (Western blot), and activity of MMP-2 and MMP-9 (zymography) were evaluated. The protease CAT induced COL1 expression in explants, at both estrous cycle phases and treatment times. The inhibitory effect of INH was observed on COL1A2 transcripts in follicular phase at 24-h treatment, and in midluteal phase at 48 h (P < 0.05), and on the relative abundance of COL protein in follicular phase and midluteal phase explants, at 48 h (P < 0.001). Our study suggests that MMP-2 might also be involved in an earlier response to CAT, and MMP-9 in a later response, mainly in the follicular phase. While the use of INH reduced CAT-induced COL1 endometrial expression, MMPs might be involved in the fibrogenic response to CAT. Therefore, in mare endometrium, the use of INH may be a future potential therapeutic means to reduce CAT-induced COL1 formation and to hamper endometrosis establishment.info:eu-repo/semantics/publishedVersio
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