709 research outputs found

    Perturbations in Lineage Specification of Granulosa and Theca Cells May Alter Corpus Luteum Formation and Function

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    Anovulation is a major cause of infertility, and it is the major leading reproductive disorder in mammalian females. Without ovulation, an oocyte is not released from the ovarian follicle to be fertilized and a corpus luteum is not formed. The corpus luteum formed from the luteinized somatic follicular cells following ovulation, vasculature cells, and immune cells is critical for progesterone production and maintenance of pregnancy. Follicular theca cells differentiate into small luteal cells (SLCs) that produce progesterone in response to luteinizing hormone (LH), and granulosa cells luteinize to become large luteal cells (LLCs) that have a high rate of basal production of progesterone. The formation and function of the corpus luteum rely on the appropriate proliferation and differentiation of both granulosa and theca cells. If any aspect of granulosa or theca cell luteinization is perturbed, then the resulting luteal cell populations (SLC, LLC, vascular, and immune cells) may be reduced and compromise progesterone production. Thus, many factors that affect the differentiation/lineage of the somatic cells and their gene expression profiles can alter the ability of a corpus luteum to produce the progesterone critical for pregnancy. Our laboratory has identified genes that are enriched in somatic follicular cells and luteal cells through gene expression microarray. This work was the first to compare the gene expression profiles of the four somatic cell types involved in the follicle-to-luteal transition and to support previous immunofluorescence data indicating theca cells differentiate into SLCs while granulosa cells become LLCs. Using these data and incorporating knowledge about the ways in which luteinization can go awry, we can extrapolate the impact that alterations in the theca and granulosa cell gene expression profiles and lineages could have on the formation and function of the corpus luteum. While interactions with other cell types such as vascular and immune cells are critical for appropriate corpus luteum function, we are restricting this review to focus on granulosa, theca, and luteal cells and how perturbations such as androgen excess and inflammation may affect their function and fertility

    Neutrophil to lymphocyte ratio and cancer prognosis: an umbrella review of systematic reviews and meta-analyses of observational studies

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    Background Although neutrophils have been linked to the progression of cancer, uncertainty exists around their association with cancer outcomes, depending on the site, outcome and treatments considered. We aimed to evaluate the strength and validity of evidence on the association between either the neutrophil to lymphocyte ratio (NLR) or tumour-associated neutrophils (TAN) and cancer prognosis. Methods We searched MEDLINE, Embase and Cochrane Database of Systematic Reviews from inception to 29 May 2020 for systematic reviews and meta-analyses of observational studies on neutrophil counts (here NLR or TAN) and specific cancer outcomes related to disease progression or survival. The available evidence was graded as strong, highly suggestive, suggestive, weak or uncertain through the application of pre-set GRADE criteria. Results A total of 204 meta-analyses from 86 studies investigating the association between either NLR or TAN and cancer outcomes met the criteria for inclusion. All but one meta-analyses found a hazard ratio (HR) which increased risk (HR > 1). We did not find sufficient meta-analyses to evaluate TAN and cancer outcomes (N = 9). When assessed for magnitude of effect, significance and bias related to heterogeneity and small study effects, 18 (9%) associations between NLR and outcomes in composite cancer endpoints (combined analysis), cancers treated with immunotherapy and some site specific cancers (urinary, nasopharyngeal, gastric, breast, endometrial, soft tissue sarcoma and hepatocellular cancers) were supported by strong evidence. Conclusion In total, 60 (29%) meta-analyses presented strong or highly suggestive evidence. Although the NLR and TAN hold clinical promise in their association with poor cancer prognosis, further research is required to provide robust evidence, assess causality and test clinical utility

    Respiratory Tract Infection Related Healthcare Utilisation in UK Children with Down's Syndrome

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    Effect of antibiotics in preventing hospitalizations from respiratory tract infections in children with Down syndrome

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    BACKGROUND: Children with Down Syndrome (DS) are at high risk of respiratory tract infections (RTIs) due to anatomical variations, comorbidities and immune system immaturity. Evidence on interventions to reduce this risk is incomplete. This study aims to quantify the effect of antibiotics prescribed for RTIs in primary care on the subsequent risk of RTI-related hospitalisation for children with DS versus controls. METHODS: We conducted a retrospective cohort study of 992 children with DS and 4,874 controls managed by UK National Health Service (NHS) General Practitioners (GPs) and hospitals as identified in CALIBER (Clinical disease research using LInked Bespoke studies and Electronic health Records), 1997-2010. Univariate and multivariate logistic regression were undertaken. RESULTS: In children with DS, the prescription of antibiotics following an RTI-related GP consultation did not significantly reduce the risk of RTI-related hospitalisation in the subsequent 28 days (Risk with antibiotics 1.8%; without 2.5%; Risk Ratio (RR) 0.699, 95% Confidence Interval (CI) 0.471-1.036). Subgroup analyses showed a risk reduction only in infants with DS, after adjustment for covariates. There was no reduction in risk for controls, overall or across subgroups. CONCLUSIONS: In conclusion, whilst prescription of antibiotics following RTI-related GP consultations were effective for infants with DS in reducing subsequent RTI-related hospitalisation, this was not the case for older children with DS. We would encourage further high-quality cohort and randomised controlled trials to interrogate this finding, and to examine the impact of antibiotics on other endpoints, including symptom duration. This article is protected by copyright. All rights reserved

    Vascular Endothelial Growth Factor and Kinase Domain Region Receptor Are Involved in Both Seminiferous Cord Formation and Vascular Development During Testis Morphogenesis in the Rat

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    Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P \u3c 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P \u3c 0.01). To determine signal transduction pathways involved in VEGFA’s regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (PI3K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the PI3K pathway during testis morphogenesis to elicit its effects

    Action of Retinoids on Embryonic and Early Postnatal Testis Development

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    The current study investigates the hypothesis that retinoids have a role in embryonic testis development. The action of retinoids on testis development and the expression of retinoic acid receptors (RARα, RARβ, RARγ) were examined. In embryonic day 13 (E13; plug date 5 E0) testis organ cultures an RAR-selective agonist and alltrans retinoic acid completely inhibited seminiferous cord formation. In contrast, an RARα-selective antagonist had no effect. RT-PCR demonstrated that RARα messenger RNA (mRNA) was expressed at all developmental time points evaluated, which included embryonic day 14 (E14) through postnatal day 30 (P30). Expression of RARβ mRNA was present at E15 through P2, whereas RARγ mRNA was expressed at E18 through P2. Cellular localization of receptors by immunohistochemistry indicated that RARα was localized to the interstitium at E18 and to the seminiferous cords by P0. RARβ and RARγ were detected in both interstitium and cords at E16 and by E18 were mainly expressed in the cords. At P0 RARβ and RARγ were localized to the germ cell populations. To examine retinoid actions, the growth of P0 testis cultures were investigated. Interestingly, retinol and retinoic acid did not inhibit growth of P0 testis cultures but did inhibit the action of growth stimulators. Retinoic acid inhibited FSH, EGF, and 10% calf serum stimulated growth in P0 testis cultures. The hypothesis tested was that the inhibitory effects of retinoids on P0 testis growth may be mediated through the growth inhibitor, transforming growth factor-b (TGFβ). The action of retinoids on TGFβ mRNA expression was examined in P0 testis cultures. Retinoic acid stimulated TGFβ3 mRNA expression within 24 h and increased expression of TGFβ1 and TGFβ2 after 72 h. Retinol increased expression of TGFβ1 and TGFβ2 but not TGFβ3 after 72 h of treatment. These observations indicate that retinoic acid can influence seminiferous cord formation and testis growth. The inhibitory actions of retinoids may in part be mediated through increased expression of TGFβ isoforms

    Vascular Endothelial Growth Factor and Kinase Domain Region Receptor Are Involved in Both Seminiferous Cord Formation and Vascular Development During Testis Morphogenesis in the Rat

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    Morphological male sex determination is dependent on migration of endothelial and preperitubular cells from the adjacent mesonephros into the developing testis. Our hypothesis is that VEGFA and its receptor KDR are necessary for both testicular cord formation and neovascularization. The Vegfa gene has 8 exons with many splice variants. Vegfa120, Vegfa164, and Vegfa188 mRNA isoforms were detected on Embryonic Day (E) 13.5 (plug date = E0) in the rat. Vegfa120, Vegfa144, Vegfa164, Vegfa188, and Vegfa205 mRNA were detected at E18 and Postnatal Day 3 (P3). Kdr mRNA was present on E13.5, whereas Fms-like tyrosine kinase 1 receptor (Flt1) mRNA was not detected until E18. VEGFA protein was localized to Sertoli cells at cord formation and KDR to germ and interstitial cells. The VEGFA signaling inhibitors SU1498 (40 μM) and VEGFR-TKI (8 μM) inhibited cord formation in E13 testis cultures with 90% reduced vascular density (P \u3c 0.01) in VEGFR-TKI-treated organs. Furthermore, Je-11 (10 μM), an antagonist to VEGFA, also perturbed cord formation and inhibited vascular density by more than 50% (P \u3c 0.01). To determine signal transduction pathways involved in VEGFA’s regulation of testis morphogenesis, E13 testis were treated with LY 294002 (15 μM), a phosphoinositide 3-kinase (PI3K) pathway inhibitor, resulting in inhibition of both vascular density (46%) and cord formation. Thus, we support our hypothesis and conclude that VEGFA, secreted by the Sertoli cell, is involved in both neovascularization and cord formation and potentially acts through the PI3K pathway during testis morphogenesis to elicit its effects

    'Birthing a Better Future': A mixed-methods evaluation of an exhibition on the early years of life

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    BACKGROUND: Our study aimed to evaluate to what extent Zero2 Expo's 'Birthing a Better Future', a co-created multimedia exhibition, was effective in raising awareness on the importance of the first 1001 days of life and explore what refinements would help to optimize the impact of future exhibitions. METHODS: We conducted a mixed-methods evaluation of the exhibition delivered in the John Radcliffe Hospital, Oxford. Through convenience sampling, 14 participants were selected to participate in 12 structured interviews and 19 participants completed a questionnaire. Interviews were thematically analysed alongside quantitative analysis of questionnaire responses through Likert scales. RESULTS: The majority (78.6%, n = 11/14) of participants who completed the questionnaire either agreed or strongly agreed that the exhibition raised their awareness about the first 1001 days of life. This was supported by the analysis of interviews. The use of art was found to provoke an emotional engagement from participants. Participants felt that the length of the written pieces and location of the exhibition were important factors for designers to consider in future exhibitions. CONCLUSION: This study demonstrated that multimedia exhibitions, combining science with art, may be an effective way to raise awareness of public health messages. Engaging with key stakeholders will be an essential step in order to improve future public health exhibitions. PUBLIC CONTRIBUTION: When designing the study, the public reviewed the study tools, which were refined based on their feedback. At every phase of the study, members of the public who are artists co-created the exhibition content
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