142 research outputs found

    Kv7 and Kv11 channels in myometrial regulation.

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    Ion channels play a key role in defining myometrial contractility. Modulation of ion channel populations is proposed to underpin gestational changes in uterine contractility associated with the transition from uterine quiescence to active labour. Of the myriad ion channels present in the uterus, this article will focus upon potassium channels encoded by the KCNQ genes and ether-à-go-go-related (ERG) genes. Voltage-gated potassium channels encoded by KCNQ and ERG (termed Kv7 and Kv11, respectively) are accepted as major determinants of neuronal excitability and the duration of the cardiac action potential. However, there is now growing appreciation that these ion channels have a major functional impact in vascular and non-vascular smooth muscle. Moreover, Kv7 channels may be potential therapeutic targets for the treatment of preterm labour

    Neonatal weight loss and gain patterns in caesarean section born infants : integrative systematic review

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    There is evidence that caesarean section delivery can impact on neonatal weight loss and weight gain patterns in the first 5 days of life. We conducted an integrative systematic review to examine the association of mode of delivery on early neonatal weight loss. Pubmed, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Excerpta Medica dataBASE, and Medical Literature Analysis and Retrieval System Online were searched for relevant papers published before June 2019. Reference lists from the relevant papers were then backwards and forwards searched. As neonatal weight loss was reported in different formats, a meta‐analysis could not be carried out. Most studies did not distinguish between elective and emergency caesarean sections or instrumental and nonassisted vaginal deliveries. Seven papers were included. All papers except one found that caesarean section was associated with higher weight loss in the early days of life. Two papers presented data from studies on babies followed up to 1 month. One study found that on day 25, babies born by caesarean section had significantly higher weight gain than those born vaginally, while another found that by day 28, babies born vaginally gained more weight per day (11.9 g/kg/day) than those born by caesarean section (10.9 g/kg/day; p = .02). Overall, infants born by caesarean section lost more weight than those born vaginally, but due to the small number of studies included, more are needed to look at this difference and why it may occur. This discrepancy in weight between the two groups may be corrected over time, but future studies will need larger sample sizes and longer follow‐up periods to examine this

    PRECISE pregnancy cohort: challenges and strategies in setting up a biorepository in sub-Saharan Africa

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    Background and objective: PRECISE is a population-based, prospective pregnancy cohort study designed for deep phenotyping of pregnancies in women with placenta-related disorders, and in healthy controls. The PRECISE Network is recruiting ~ 10,000 pregnant women in three countries (The Gambia, Kenya, and Mozambique) representing sub-Saharan Africa. The principal aim is to improve our understanding of pre-eclampsia, fetal growth restriction and stillbirth. This involves the creation of a highly curated biorepository for state of the art discovery science and a rich database of antenatal variables and maternal and neonatal outcomes. Our overarching aim is to provide large sample numbers with adequate power to address key scientific questions. Here we describe our experience of establishing a biorepository in the PRECISE Network and review the issues and challenges surrounding set-up, management and scientific use. Methods: The feasibility of collecting and processing each sample type was assessed in each setting and plans made for establishing the necessary infrastructure. Quality control (QC) protocols were established to ensure that biological samples are \u27fit-for-purpose\u27. The management structures required for standardised sample collection and processing were developed. This included the need for transport of samples between participating countries and to external academic/commercial institutions. Results: Numerous practical challenges were encountered in setting up the infrastructure including facilities, staffing, training, cultural barriers, procurement, shipping and sample storage. Whilst delaying the project, these were overcome by establishing good communication with the sites, training workshops and constant engagement with the necessary commercial suppliers. A Project Executive Committee and Biology Working Group together defined the biospecimens required to answer the research questions paying particular attention to harmonisation of protocols with other cohorts so as to enable cross-biorepository collaboration. Governance structures implemented include a Data and Sample Committee to ensure biospecimens and data will be used according to consent, and prioritisation by scientific excellence. A coordinated sample and data transfer agreement will prevent delay in sample sharing. Discussion: With adequate training and infrastructure, it is possible to establish high quality sample collections to facilitate research programmes such as the PRECISE Network in sub-Saharan Africa. These preparations are pre-requisites for effective execution of a biomarker-based approach to better understand the complexities of placental disease in these settings, and others

    Expression of voltage-dependent potassium channels in first trimester human placentae

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    Potassium channel α-subunits encoded by KCNQ1-5 genes form voltage-dependent channels (Kv7), modulated by KCNE1-5 encoded accessory proteins. The aim was to determine KCNQ and KCNE mRNA expression and assess protein expression/localisation of the KCNQ3 and KCNE5 isoforms in first trimester placental tissue. Placentae were obtained from women undergoing elective surgical termination of pregnancy (TOP) at 10 weeks’ (mid TOP) gestations. KCNQ1-5 expression was unchanged during the first trimester. KCNE5 expression increased in mid TOP vs. early TOP samples (P=0.022). This novel study reports mRNA and protein expression of Kv7 channels in first trimester placentae

    The PRECISE (PREgnancy Care Integrating translational Science, Everywhere) Network’s first protocol: deep phenotyping in three sub-Saharan African countries

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    Background: The PRECISE (PREgnancy Care Integrating translational Science, Everywhere) Network is a new and broadly-based group of research scientists and health advocates based in the UK, Africa and North America. Methods: This paper describes the protocol that underpins the clinical research activity of the Network, so that the investigators, and broader global health community, can have access to ‘deep phenotyping’ (social determinants of health, demographic and clinical parameters, placental biology and agnostic discovery biology) of women as they advance through pregnancy to the end of the puerperium, whether those pregnancies have normal outcomes or are complicated by one/more of the placental disorders of pregnancy (pregnancy hypertension, fetal growth restriction and stillbirth). Our clinical sites are in The Gambia (Farafenni), Kenya (Kilifi County), and Mozambique (Maputo Province). In each country, 50 non-pregnant women of reproductive age will be recruited each month for 1 year, to provide a final national sample size of 600; these women will provide culturally-, ethnically-, seasonallyand spatially-relevant control data with which to compare women with normal and complicated pregnancies. Between the three countries we will recruit ≈10,000 unselected pregnant women over 2 years. An estimated 1500 women will experience one/more placental complications over the same epoch. Importantly, as we will have accurate gestational age dating using the TraCer device, we will be able to discriminate between fetal growth restriction and preterm birth. Recruitment and follow-up will be primarily facility-based and will include women booking for antenatal care, subsequent visits in the third trimester, at time-of-disease, when relevant, during/ immediately after birth and 6 weeks after birth. Conclusions: To accelerate progress towards the women’s and children’s health-relevant Sustainable Development Goals, we need to understand how a variety of social, chronic disease, biomarker and pregnancy-specific determinants health interact to result in either a resilient or a compromised pregnancy for either mother or fetus/ newborn, or both. This protocol has been designed to create such a depth of understanding. We are seeking funding to maintain the cohort to better understand the implications of pregnancy complications for both maternal and child health

    Novel expression and regulation of voltage-dependent potassium (KV7) channels in placentae from women with preeclampsia

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    Preeclampsia is associated with structural/functional alterations in placental and maternal vasculature. KV7 (voltage-dependant potassium channels encoded by KCNQ1-5 genes) have been detected in several types of blood vessels where they promote vascular relaxation. KV7 channel function can be modulated by KCNE1-5 encoded accessory proteins. The aim of this study was to determine whether KCNQ and KCNE genes are differentially expressed in placentae from women with preeclampsia compared to normotensive controls and to examine any differences in those who delivered preterm (<37 weeks’) or term. Placental biopsies (from midway between the cord and periphery) were obtained, with consent, from White European control (n=24, term) and preeclamptic (n=22; of whom 8 delivered before 37 weeks’) women. KCNQ/KCNE and GAPDH mRNA expression was determined by qRT-PCR. Protein expression/localisation was assessed using immunohistochemistry. KCNQ3 and KCNE5 mRNA expression was significantly up-regulated in preeclampsia (median [IQR]: 1.942 [0.905, 3.379]) versus controls (0.159 [0.088, 0.288]; p=0.001) and exhibited a strong positive correlation with each other (p<0.001) suggesting a novel heterodimer. Enhanced protein expression of KCNQ3 and KCNE5 in preeclampsia was confirmed with localisation mainly restricted to the syncytiotrophoblast. KCNQ4 and KCNE1 isoforms were suppressed in placenta from term preeclamptic women versus controls (p≤0.05). KCNQ1 mRNA expression was increased and KCNQ5 decreased in the preterm preeclamptic group versus controls (p<0.05). In summary, KV7 channels are expressed and markedly modulated in placenta from preeclamptic women. Differential expression of isoforms may lead to altered cell proliferation. The correlation between KCNQ3 and KCNE5 expression is indicative of a novel channel complex and warrants further investigation

    Stretch Activates Human Myometrium via ERK, Caldesmon and Focal Adhesion Signaling

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    An incomplete understanding of the molecular mechanisms responsible for myometrial activation from the quiescent pregnant state to the active contractile state during labor has hindered the development of effective therapies for preterm labor. Myometrial stretch has been implicated clinically in the initiation of labor and the etiology of preterm labor, but the molecular mechanisms involved in the human have not been determined. We investigated the mechanisms by which gestation-dependent stretch contributes to myometrial activation, by using human uterine samples from gynecologic hysterectomies and Cesarean sections. Here we demonstrate that the Ca requirement for activation of the contractile filaments in human myometrium increases with caldesmon protein content during gestation and that an increase in caldesmon phosphorylation can reverse this inhibitory effect during labor. By using phosphotyrosine screening and mass spectrometry of stretched human myometrial samples, we identify 3 stretch-activated focal adhesion proteins, FAK, p130Cas, and alpha actinin. FAK-Y397, which signals integrin engagement, is constitutively phosphorylated in term human myometrium whereas FAK-Y925, which signals downstream ERK activation, is phosphorylated during stretch. We have recently identified smooth muscle Archvillin (SmAV) as an ERK regulator. A newly produced SmAV-specific antibody demonstrates gestation-specific increases in SmAV protein levels and stretch-specific increases in SmAV association with focal adhesion proteins. Thus, whereas increases in caldesmon levels suppress human myometrium contractility during pregnancy, stretch-dependent focal adhesion signaling, facilitated by the ERK activator SmAV, can contribute to myometrial activation. These results suggest that focal adhesion proteins may present new targets for drug discovery programs aimed at regulation of uterine contractility

    Culturally informed resilience in conflict settings: A literature review of Sumud in the occupied Palestinian territories

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    Investigating culturally specific views and experiences of trauma and resilience can offer new insights that can aid distress management, meaning making, coping and resilience in adverse conditions, and inform emergency and disaster responses. Sumud is a Palestinian cultural construct and component of resilience in the occupied Palestinian territories (oPt). Sumud in Arabic refers to steadfastness or perseverance. This literature review focuses on research studies on Sumud in the oPt, with particular attention on the meaning and manifestations of Sumud, the role of non-violent resistance, and how Sumud and non-violent resistance informs resilience and coping in the context of a military occupation, protracted political conflict, and chronic adversity. The peer-reviewed literature was surveyed using the PubMed and PsycINFO databases. The findings indicate how Sumud is a central component of resilience and provides a meta-cognitive framework which Palestinians use to interpret, cope and respond to ongoing injustice and traumatic experiences, engendering a sense of purpose and meaning. It is both a value and an action that manifests via individual and collective action to protect family and community survival, wellbeing, dignity, Palestinian identity and culture, and a determination to remain on the land. The implications of this study and the relevance of the findings to mental health and disaster relief are considered

    Microbiota dynamics, metabolic and immune interactions in the cervicovaginal environment and their role in spontaneous preterm birth

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    Differences in the cervicovaginal microbiota are associated with spontaneous preterm birth (sPTB), a significant cause of infant morbidity and mortality. Although establishing a direct causal link between cervicovaginal microbiota and sPTB remains challenging, recent advancements in sequencing technologies have facilitated the identification of microbial markers potentially linked to sPTB. Despite variations in findings, a recurring observation suggests that sPTB is associated with a more diverse and less stable vaginal microbiota across pregnancy trimesters. It is hypothesized that sPTB risk is likely to be modified via an intricate host-microbe interactions rather than due to the presence of a single microbial taxon or broad community state. Nonetheless, lactobacilli dominance is generally associated with term outcomes and contributes to a healthy vaginal environment through the production of lactic acid/ maintenance of a low pH that excludes other pathogenic microorganisms. Additionally, the innate immunity of the host and metabolic interactions between cervicovaginal microbiota, such as the production of bacteriocins and the use of proteolytic enzymes, exerts a profound influence on microbial populations, activities, and host immune responses. These interplays collectively impact pregnancy outcomes. This review aims to summarize the complexity of cervicovaginal environment and microbiota dynamics, and associations with bacterial vaginosis and sPTB. There is also consideration on how probiotics may mitigate the risk of sPTB and bacterial vaginosis
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