279 research outputs found
The paracrinology of tubal ectopic pregnancy
As part of successful human reproduction, the Fallopian tube must provide a suitable environment for pre-implantation development of the embryo and for efficient transport of the embryo to the uterus for implantation. These functions are coordinated by paracrine interactions between tubal epithelial, smooth muscle and immune cells and the cells of the developing embryo. Alterations in these signals can lead to a tubal microenvironment encouraging of embryo implantation and to dysregulated tubal motility, ultimately resulting in inappropriate and early implantation of the embryo in the Fallopian tube. Here, we highlight novel and emerging concepts in tubal physiology and pathobiology, such as the induction of a receptive phenotype within the Fallopian tube, leading to ectopic implantation. Chlamydia trachomatis infection is a risk factor for tubal ectopic pregnancy. Activation of toll-like receptor 2 (TLR-2) in the Fallopian tube epithelium, by C. trachomatis has recently been demonstrated, leading to the dysregulation of factors involved in implantation and smooth muscle contractility, such as prokineticins (PROK), activin A and interleukin 1 (IL-1). The Fallopian tube has also recently been shown to harbour a unique population of immune cells, compared to the endometrium. In addition, the complement of immune cells in the Fallopian tube has been reported to be altered in Fallopian tube from women with ectopic pregnancy. There are increasing data suggesting that vascularisation of the Fallopian tube, by the embryo during ectopic pregnancy, differs from that initiated in the uterus during normal pregnancy. This too, is likely the result of paracrine signals between the embryo and the tubal microenvironment
Placental Growth Factor:A Promising Diagnostic Biomarker for Tubal Ectopic Pregnancy
CONTEXT: Tubal ectopic pregnancy is common but accurate diagnosis is difficult and costly. There is currently no serum test to differentiate tubal from intrauterine implantation and an effective biomarker of ectopic pregnancy would be a major clinical advance. OBJECTIVE: A key feature of successful intrauterine implantation is the establishment of a supportive vascular network and this has been associated with the activity of placental growth factor (PIGF). We hypothesized that the local decidual environment facilitates PIGF-dependent angiogenesis and that this pathway is not active in tubal implantation. We aimed to determine whether tubal implantation is manifest by an attenuation of the normal trophoblast PIGF-response and whether serum PIGF levels are different in ectopic compared to intrauterine pregnancy. DESIGN: Tissue and serum analysis. SETTING: A large UK teaching hospital. PATIENTS: Gestation-matched pregnant women undergoing surgical termination of pregnancy (viable intrauterine) (n=15), evacuation of uterus for embryonic missed miscarriage (non-viable intrauterine) (n=10) and surgery for tubal ectopic pregnancy (n=15). INTERVENTIONS: Trophoblast was examined by immunohistochemistry and quantitative RT-PCR, and serum was analyzed by ELISA. RESULTS: PIGF was localized to the cytotrophoblast cells. Expression of PIGF mRNA was reduced in trophoblast isolated from women with ectopic compared to intrauterine pregnancies (P<0.05). Serum PIGF was undetectable in women with tubal ectopic pregnancies and reduced, or undetectable, in miscarriage compared to viable intrauterine pregnancies (P<0.01). CONCLUSIONS: Serum PIGF is a promising novel diagnostic biomarker for early pregnancy location and outcome, and large-scale studies are now required to determine its clinical utility
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The impact of mental health recovery narratives on recipients experiencing mental health problems: Qualitative analysis and change model.
BACKGROUND: Mental health recovery narratives are stories of recovery from mental health problems. Narratives may impact in helpful and harmful ways on those who receive them. The objective of this paper is to develop a change model identifying the range of possible impacts and how they occur. METHOD: Semi-structured interviews were conducted with adults with experience of mental health problems and recovery (n = 77). Participants were asked to share a mental health recovery narrative and to describe the impact of other people's recovery narratives on their own recovery. A change model was generated through iterative thematic analysis of transcripts. RESULTS: Change is initiated when a recipient develops a connection to a narrator or to the events descripted in their narrative. Change is mediated by the recipient recognising experiences shared with the narrator, noticing the achievements or difficulties of the narrator, learning how recovery happens, or experiencing emotional release. Helpful outcomes of receiving recovery narratives are connectedness, validation, hope, empowerment, appreciation, reference shift and stigma reduction. Harmful outcomes are a sense of inadequacy, disconnection, pessimism and burden. Impact is positively moderated by the perceived authenticity of the narrative, and can be reduced if the recipient is experiencing a crisis. CONCLUSIONS: Interventions that incorporate the use of recovery narratives, such as peer support, anti-stigma campaigns and bibliotherapy, can use the change model to maximise benefit and minimise harms from narratives. Interventions should incorporate a diverse range of narratives available through different mediums to enable a range of recipients to connect with and benefit from this material. Service providers using recovery narratives should preserve authenticity so as to maximise impact, for example by avoiding excessive editing
The mechanisms and processes of connection: developing a causal chain model capturing impacts of receiving recorded mental health recovery narratives.
BACKGROUND: Mental health recovery narratives are a core component of recovery-oriented interventions such as peer support and anti-stigma campaigns. A substantial number of recorded recovery narratives are now publicly available online in different modalities and in published books. Whilst the benefits of telling one's story have been investigated, much less is known about how recorded narratives of differing modalities impact on recipients. A previous qualitative study identified connection to the narrator and/or to events in the narrative to be a core mechanism of change. The factors that influence how individuals connect with a recorded narrative are unknown. The aim of the current study was to characterise the immediate effects of receiving recovery narratives presented in a range of modalities (text, video and audio), by establishing the mechanisms of connection and the processes by which connection leads to outcomes. METHOD: A study involving 40 mental health service users in England was conducted. Participants were presented with up to 10 randomly-selected recovery narratives and were interviewed on the immediate impact of each narrative. Thematic analysis was used to identify the mechanisms of connection and how connection leads to outcome. RESULTS: Receiving a recovery narrative led participants to reflect upon their own experiences or those of others, which then led to connection through three mechanisms: comparing oneself with the narrative and narrator; learning about other's experiences; and experiencing empathy. These mechanisms led to outcomes through three processes: the identification of change (through attending to narrative structure); the interpretation of change (through attending to narrative content); and the internalisation of interpretations. CONCLUSIONS: This is the first study to identify mechanisms and processes of connection with recorded recovery narratives. The empirically-based causal chain model developed in this study describes the immediate effects on recipients. This model can inform selection of narratives for use in interventions, and be used to support peer support workers in recounting their own recovery narratives in ways which are maximally beneficial to others
Sofosbuvir/velpatasvir for 12 vs. 6 weeks for the treatment of recently acquired hepatitis C infection.
BACKGROUND AND AIMS
Shortened duration therapy for acute and recent hepatitis C virus (HCV) infection has been shown to be highly effective in several small non-randomised studies with direct-acting antiviral regimens, however large randomised studies are lacking.
METHODS
REACT was an NIH-funded multicentre international, open-label, randomised, phase 4 non-inferiority trial examining the efficacy of short course (6 weeks) versus standard course (12 weeks) therapy with sofosbuvir-velpatasvir for recent HCV infection (estimated duration of infection <= 12 months). Randomisation occurred at week 6. The primary endpoint was SVR12 in the intention-to treat (ITT) population. A total of 250 participants were planned for enrolment. On advice of the data safety and monitoring board the study was halted early.
RESULTS
Primary analysis population consisted of 188 randomised participants at termination of study enrolment; short arm (n=93), standard arm (n=95). Ninety seven percent were male and 69% HIV positive. ITT SVR12 was 76/93, 81.7% (95% CI 72.4-89.0) in the short arm and 86/95, 90.5% (95% CI 82.7-95.6) in the standard arm. The difference between the arms was -8.8 (95% CI: -18.6, 1.0). By modified ITT analysis in which non-virological reasons for failure were excluded (death, reinfection, lost to follow-up) SVR12 was 76/85, 89.4% (95% CI 80.8-95.0) in the short arm and 86/88, 97.7% in the standard arm (95% CI 92.0-99.7; difference -8.3%, p=0.025).
CONCLUSIONS
In this randomised study in recent HCV infection, 6 weeks sofosbuvir-velpatasvir did not meet the criteria for non-inferiority to standard 12 weeks duration.
LAY SUMMARY
In this randomised trial one hundred and eighty people with recently acquired hepatitis C infection were randomly assigned to treatment using either a short 6-week course (93 people) or standard 12-week course (95 people) of the hepatitis C treatment sofosbuvir/velpatasvir. There were nine cases of relapse after treatment in the short course and two using the standard course. A shortened course of 6 weeks therapy for hepatitis C infection was considered not as effective as a standard twelve week course in people with recently acquired hepatitis C infection.
TRIAL REGISTRATION
Clinicaltrials.gov Identifier: NCT02625909
Chlamydia trachomatis infection increases fallopian tube PROKR2 via TLR2 and NFκB activation resulting in a microenvironment predisposed to ectopic pregnancy
Chlamydia trachomatis and smoking are major risk factors for tubal ectopic pregnancy (EP), but the underlying mechanisms of these associations are not completely understood. Fallopian tube (FT) from women with EP exhibit altered expression of prokineticin receptors 1 and 2 (PROKR1 and PROKR2); smoking increases FT PROKR1, resulting in a microenvironment predisposed to EP. We hypothesize that C. trachomatis also predisposes to EP by altering FT PROKR expression and have investigated this by examining NFkappaB activation via ligation of the Toll-like receptor (TLR) family of cell-surface pattern recognition receptors. PROKR2 mRNA was higher in FT from women with evidence of past C. trachomatis infection than in those without (P < 0.05), and was also increased in FT explants and in oviductal epithelial cell line OE-E6/E7 infected with C. trachomatis (P < 0.01) or exposed to UV-killed organisms (P < 0.05). The ability of both live and dead organisms to induce this effect suggests ligation of a cell-surface-expressed receptor. FT epithelium and OE-E6/E7 were both found to express TLR2 and TLR4 by immunohistochemistry. Transfection of OE-E6/E7 cells with dominant-negative TLR2 or IkappaBalpha abrogated the C. trachomatis-induced PROKR2 expression. We propose that ligation of tubal TLR2 and activation of NFkappaB by C. trachomatis leads to increased tubal PROKR2, thereby predisposing the tubal microenvironment to ectopic implantation
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The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)
The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds
Adherence to sofosbuvir and velpatasvir among people with chronic HCV infection and recent injection drug use:The SIMPLIFY study
BACKGROUND:This study investigated treatment adherence among people with recent injecting drug use in a study of sofosbuvir/velpatasvir therapy for HCV infection. METHODS:SIMPLIFY is an international open-label, single-arm multicentre study that recruited participants with recent injecting drug use (previous six months) and chronic HCV genotype (G) 1-6 infection between March and October 2016 in seven countries (19 sites). Participants received sofosbuvir/velpatasvir once-daily for 12 weeks administered in a one-week electronic blister pack (records the time and date of each dose) for 12 weeks. We evaluated non-adherence (<90% adherent) as measured by electronic blister-pack assessed using logistic regression and generalised estimating equations (continuous) with detailed analyses of dosing dynamics. RESULTS:Among 103 participants, 97% (n = 100) completed treatment. Median adherence to therapy was 94%. Overall, 32% (n = 33) were considered non-adherent (<90% adherence). Adherence significantly decreased over the course of therapy. Recent stimulant injecting (cocaine and/or amphetamines) at treatment initiation and during treatment was independently associated with non-adherence. Inconsistent dose timing (standard deviation of daily dose timing of ≥240 min) was also independently associated with non-adherence to therapy. Factors associated with inconsistent dose timing included lower levels of education and recent stimulant injecting. SVR was similar among adherent and non-adherent populations (94% vs. 94%, P = 0.944). CONCLUSION:This study demonstrated high adherence to once-daily sofosbuvir/velpatasvir therapy among a population of people with recent injecting drug use. Recent stimulant injecting prior to and during DAA therapy and inconsistent dose-timing during treatment was associated with non-adherence. However, there was no impact of non-adherence on response to therapy, suggesting that adherence is not a significant barrier to successful DAA therapy in people with recent injecting drug use.Evan B.Cunningham, Janaki Amin, Jordan J.Feld, Julie Bruneau, Olav Dalgard, Jeff Powis ... et al
Fermi Large Area Telescope Constraints on the Gamma-ray Opacity of the Universe
The Extragalactic Background Light (EBL) includes photons with wavelengths
from ultraviolet to infrared, which are effective at attenuating gamma rays
with energy above ~10 GeV during propagation from sources at cosmological
distances. This results in a redshift- and energy-dependent attenuation of the
gamma-ray flux of extragalactic sources such as blazars and Gamma-Ray Bursts
(GRBs). The Large Area Telescope onboard Fermi detects a sample of gamma-ray
blazars with redshift up to z~3, and GRBs with redshift up to z~4.3. Using
photons above 10 GeV collected by Fermi over more than one year of observations
for these sources, we investigate the effect of gamma-ray flux attenuation by
the EBL. We place upper limits on the gamma-ray opacity of the Universe at
various energies and redshifts, and compare this with predictions from
well-known EBL models. We find that an EBL intensity in the optical-ultraviolet
wavelengths as great as predicted by the "baseline" model of Stecker et al.
(2006) can be ruled out with high confidence.Comment: 42 pages, 12 figures, accepted version (24 Aug.2010) for publication
in ApJ; Contact authors: A. Bouvier, A. Chen, S. Raino, S. Razzaque, A.
Reimer, L.C. Reye
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