1,942 research outputs found
Advances in prevention and therapy of neonatal dairy calf diarrhoea : a systematical review with emphasis on colostrum management and fluid therapy
Neonatal calf diarrhoea remains the most common cause of morbidity and mortality in preweaned dairy calves worldwide. This complex disease can be triggered by both infectious and non-infectious causes. The four most important enteropathogens leading to neonatal dairy calf diarrhoea are Escherichia coli, rota-and coronavirus, and Cryptosporidium parvum. Besides treating diarrhoeic neonatal dairy calves, the veterinarian is the most obvious person to advise the dairy farmer on prevention and treatment of this disease. This review deals with prevention and treatment of neonatal dairy calf diarrhoea focusing on the importance of a good colostrum management and a correct fluid therapy
Piezo1 channels are mechanosensors in human fetoplacental endothelial cells
Study question: Does the shear stress sensing ion channel subunit Piezo1 have an important mechanotransduction role in human fetoplacental endothelium?
Summary answer: Piezo1 is present and functionally active in human fetoplacental endothelial cells, and disruption of Piezo1 prevents the normal response to shear stress.
What is known already: Shear stress is an important stimulus for maturation and function of placental vasculature but the molecular mechanisms by which the force is detected and transduced are unclear. Piezo1 channels are Ca2+-permeable non-selective cationic channels which are critical for shear stress sensing and maturation of murine embryonic vasculature.
Study design, samples/materials, methods: We investigated the relevance of Piezo1 to placental vasculature by studying human fetoplacental endothelial cells (FpECs) from healthy pregnancies. Endothelial cells were isolated from placental cotyledons and cultured, for the study of tube formation and cell alignment to shear stress. In addition, human placental arterial endothelial cells were isolated and studied immediately by patch-clamp electrophysiology.
Main results and the role of chance: The synthetic Piezo1 channel agonist Yoda1 caused strong elevation of the intracellular Ca2+ concentration with a 50% effect occurring at about 5.4 μM. Knockdown of Piezo1 by RNA interference suppressed the Yoda1 response, consistent with it being mediated by Piezo1 channels. Alignment of cells to the direction of shear stress was also suppressed by Piezo1 knockdown without loss of cell viability. Patch-clamp recordings from freshly isolated endothelium showed shear stress-activated single channels which were characteristic of Piezo1.
Limitations, reasons for caution: The in vitro nature of fetoplacental endothelial cell isolation and subsequent culture may affect FpEC characteristics and PIEZO1 expression. In addition to Piezo1, alternative shear stress sensing mechanisms have been suggested in other systems and might also contribute in the placenta.
Wider implications of the findings: These data suggest that Piezo1 is an important molecular determinant of blood flow sensitivity in the placenta. Establishing and manipulating the molecular mechanisms regulating shear stress sensing could lead to novel therapeutic strategies to improve blood flow in the placenta.
Large-scale data: Not applicable.
Study funding/competing interest(s): LCM was funded by a Clinical Research Training Fellowship from the Medical Research Council and by the Royal College of Obstetricians and Gynaecologists, and has received support from a Wellcome Trust Institutional Strategic Support Fund. JS was supported by the Wellcome Trust and a BHF Intermediate Research Fellowship. HJG, CW, AJH and PJW were supported by PhD Studentships from BHF, BBSRC and the Leeds Teaching Hospitals Charitable Foundation respectively. All authors declare no conflict of interest
Allele-specific miRNA-binding analysis identifies candidate target genes for breast cancer risk
Most breast cancer (BC) risk-associated single-nucleotide polymorphisms (raSNPs) identified in genome-wide association studies (GWAS) are believed to cis-regulate the expression of genes. We hypothesise that cis-regulatory variants contributing to disease risk may be affecting microRNA (miRNA) genes and/or miRNA binding. To test this, we adapted two miRNA-binding prediction algorithms-TargetScan and miRanda-to perform allele-specific queries, and integrated differential allelic expression (DAE) and expression quantitative trait loci (eQTL) data, to query 150 genome-wide significant ( P≤5×10-8 ) raSNPs, plus proxies. We found that no raSNP mapped to a miRNA gene, suggesting that altered miRNA targeting is an unlikely mechanism involved in BC risk. Also, 11.5% (6 out of 52) raSNPs located in 3'-untranslated regions of putative miRNA target genes were predicted to alter miRNA::mRNA (messenger RNA) pair binding stability in five candidate target genes. Of these, we propose RNF115, at locus 1q21.1, as a strong novel target gene associated with BC risk, and reinforce the role of miRNA-mediated cis-regulation at locus 19p13.11. We believe that integrating allele-specific querying in miRNA-binding prediction, and data supporting cis-regulation of expression, improves the identification of candidate target genes in BC risk, as well as in other common cancers and complex diseases.Funding Agency
Portuguese Foundation for Science and Technology
CRESC ALGARVE 2020
European Union (EU)
303745
Maratona da Saude Award
DL 57/2016/CP1361/CT0042
SFRH/BPD/99502/2014
CBMR-UID/BIM/04773/2013
POCI-01-0145-FEDER-022184info:eu-repo/semantics/publishedVersio
Impact on Health-Related Quality of Life and Costs of Managing Chronic Neuropathic Pain in Academic Pain Centres: Results from a One-Year Prospective Observational Canadian Study
BACKGROUND: The management of chronic pain, including neuropathic pain (NeP), is a major public health issue. However, there is a paucity of data evaluating pain management strategies in real-life settings
The A-B transition in superfluid helium-3 under confinement in a thin slab geometry
The influence of confinement on the topological phases of superfluid 3He is
studied using the torsional pendulum method. We focus on the phase transition
between the chiral A-phase and the time-reversal-invariant B-phase, motivated
by the prediction of a spatiallymodulated (stripe) phase at the A-B phase
boundary. We confine superfluid 3He to a single 1.08 {\mu}m thick nanofluidic
cavity incorporated into a high-precision torsion pendulum, and map the phase
diagram between 0.1 and 5.6 bar. We observe only small supercooling of the
A-phase, in comparison to bulk or when confined in aerogel. This has a
non-monotonic pressure dependence, suggesting that a new intrinsic B-phase
nucleation mechanism operates under confinement, mediated by the putative
stripe phase. Both the phase diagram and the relative superfluid fraction of
the A and B phases, show that strong coupling is present at all pressures, with
implications for the stability of the stripe phase.Comment: 6 figures, 1 table + supplemental informatio
Decoherence in Crystals of Quantum Molecular Magnets
Decoherence in Nature has become one of the most pressing problems in
physics. Many applications, including quantum information processing, depend on
understanding it; and fundamental theories going beyond quantum mechanics have
been suggested [1-3], where the breakdown of quantum theory appears as an
'intrinsic decoherence', mimicking environmental decoherence [4]. Such theories
cannot be tested until we have a handle on ordinary environmental decoherence
processes. Here we show that the theory for insulating electronic spin systems
can make accurate predictions for environmental decoherence in molecular-based
quantum magnets [5]. Experimental understanding of decoherence in molecular
magnets has been limited by short decoherence times, which make coherent spin
manipulation extremely difficult [6-9]. Here we reduce the decoherence by
applying a strong magnetic field. The theory predicts the contributions to the
decoherence from phonons, nuclear spins, and intermolecular dipolar
interactions, for a single crystal of the Fe8 molecular magnet. In experiments
we find that the decoherence time varies strongly as a function of temperature
and magnetic field. The theoretical predictions are fully verified
experimentally - there are no other visible decoherence sources. Our
investigation suggests that the decoherence time is ultimately limited by
nuclear spins, and can be extended up to about 500 microseconds, by optimizing
the temperature, magnetic field, and nuclear isotopic concentrations.Comment: Submitted version including 11 pages, 3 figures and online supporting
materials. Appeared on Nature Advance Online Publication (AOP) on July 20th,
2011.
(http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10314.html
Evolutionary dynamics and biogeography of Musaceae reveal a correlation between the diversification of the banana family and the geological and climatic history of Southeast Asia
Article PurchasedTropical Southeast Asia, which harbors most of the Musaceae biodiversity, is one of the most species-rich regions in the world. Its high degree of endemism is shaped by the region's tectonic and climatic history, with large differences between northern Indo-Burma and the Malayan Archipelago. Here, we aim to find a link between the diversification and biogeography of Musaceae and geological history of the Southeast Asian subcontinent. The Musaceae family (including five Ensete, 45 Musa and one Musella species) was dated using a large phylogenetic framework encompassing 163 species from all Zingiberales families. Evolutionary patterns within Musaceae were inferred using ancestral area reconstruction and diversification rate analyses. All three Musaceae genera - Ensete, Musa and Musella - originated in northern Indo-Burma during the early Eocene. Musa species dispersed from 'northwest to southeast' into Southeast Asia with only few back-dispersals towards northern Indo-Burma. Musaceae colonization events of the Malayan Archipelago subcontinent are clearly linked to the geological and climatic history of the region. Musa species were only able to colonize the region east of Wallace's line after the availability of emergent land from the late Miocene onwards
Sex Differences in the Association between Serum Levels of Testosterone and Frailty in an Elderly Population: The Toledo Study for Healthy Aging
BACKGROUND: Age-associated decline in testosterone levels represent one of the potential mechanisms involved in the development of frailty. Although this association has been widely reported in older men, very few data are available in women. We studied the association between testosterone and frailty in women and assessed sex differences in this relationship. METHODS: We used cross-sectional data from the Toledo Study for Healthy Aging, a population-based cohort study of Spanish elderly. Frailty was defined according to Fried's approach. Multivariate odds-ratios (OR) and 95% confidence intervals (CI) associated with total (TT) and free testosterone (FT) levels were estimated using polytomous logistic regression. RESULTS: In women, there was a U-shaped relationship between FT levels and frailty (p for FT(2) = 0.03). In addition, very low levels of FT were observed in women with ≥ 4 frailty criteria (age-adjusted geometric means = 0.13 versus 0.37 in subjects with <4 components, p = 0.010). The association of FT with frailty appeared confined to obese women (p-value for interaction = 0.05).In men, the risk of frailty levels linearly decreased with testosterone (adjusted OR for frailty = 2.9 (95%CI, 1.6-5.1) and 1.6 (95%CI, 1.0-2.5), for 1 SD decrease in TT and FT, respectively). TT and FT showed association with most of frailty criteria. No interaction was found with BMI. CONCLUSION: There is a relationship between circulating levels of FT and frailty in older women. This relation seems to be modulated by BMI. The relevance and the nature of the association of FT levels and frailty are sex-specific, suggesting that different biological mechanisms may be involved
Mapping transcription mechanisms from multimodal genomic data
Background
Identification of expression quantitative trait loci (eQTLs) is an emerging area in genomic study. The task requires an integrated analysis of genome-wide single nucleotide polymorphism (SNP) data and gene expression data, raising a new computational challenge due to the tremendous size of data.
Results
We develop a method to identify eQTLs. The method represents eQTLs as information flux between genetic variants and transcripts. We use information theory to simultaneously interrogate SNP and gene expression data, resulting in a Transcriptional Information Map (TIM) which captures the network of transcriptional information that links genetic variations, gene expression and regulatory mechanisms. These maps are able to identify both cis- and trans- regulating eQTLs. The application on a dataset of leukemia patients identifies eQTLs in the regions of the GART, PCP4, DSCAM, and RIPK4 genes that regulate ADAMTS1, a known leukemia correlate.
Conclusions
The information theory approach presented in this paper is able to infer the dependence networks between SNPs and transcripts, which in turn can identify cis- and trans-eQTLs. The application of our method to the leukemia study explains how genetic variants and gene expression are linked to leukemia.National Human Genome Research Institute (U.S.) (R01HG003354)National Institute of Allergy and Infectious Diseases (U.S.) (U19 AI067854-05)National Heart, Lung, and Blood Institute (grant T32 HL007427-28)National Institutes of Health (U.S.) (grant K99 LM009826
General practitioners apply the usual care for shoulder complaints better than expected – analysis of videotaped consultations
BACKGROUND: The education and activation program (EAP) is a newly developed intervention to prevent the development of chronic shoulder complaints (SCs). Trained general practitioners (GPs) administer the EAP. The EAP addresses inadequate cognitions and maladaptive behavior related to the SCs. The effect of the EAP is evaluated in a randomized clinical trial. The aim of the present study is to use videotaped consultations to study (1) the performance of trained GPs administering the EAP and (2) the presence of key features of the EAP already embedded in usual care (UC). METHODS: Five trained GPs were videotaped while treating a standardized patient with EAP. Additionally, five GPs administering UC were videotaped. Two blinded observers evaluated the videotapes in relation to key features of the EAP which were scored on the EAP checklist. RESULTS: The mean total score on the EAP checklist was 4.7 (SD = 2.9) for the UC group and 7.1 (SD = 2.1) for the EAP group. Neither group reached a score higher than 8, which was considered to reflect an acceptable number of key EAP features. CONCLUSION: Our comparison of the presence of key features of EAP shows that the UC and EAP groups differed less than was expected. GPs in the UC group performed above expectation, with a mean total score of 4.7. Moreover, the low number of key features present in the EAP group may very well have led to a reduced effectiveness of the EAP. The results of this study can be used to optimize the training of GPs using the EAP
- …