116 research outputs found

    Developing a database for multicenter evaluation of Placenta Accreta Spectrum

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    Studies of rare, but complex clinical conditions require multicenter cooperation. The International Society for Placenta accreta spectrum (IS-PAS) have established a secure web-based database to analyze pregnancies complicated by PAS. By repeated in-person meetings of the IS-PAS, a core dataset was established. Then, a custom-made, secure online database, capable of receiving strictly anonymized patient-related textual and imaging data and allowing statistical queries was designed, tested, amended and implemented. Between 2008 and 2019, 14 IS-PAS centers across Europe and one center in the USA contributed data for all their PAS cases, containing pregnancy data for a total of 442 pregnant women. Data were analyzed by a designated data analysis sub-group of the IS-PAS. Center characteristics are presented. Based on experiences with previous versions, our new online database now allows an all-encompassing data collection. It has shown its usefulness in the current analysis project.Non peer reviewe

    A constitutive law for dense granular flows

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    A continuum description of granular flows would be of considerable help in predicting natural geophysical hazards or in designing industrial processes. However, the constitutive equations for dry granular flows, which govern how the material moves under shear, are still a matter of debate. One difficulty is that grains can behave like a solid (in a sand pile), a liquid (when poured from a silo) or a gas (when strongly agitated). For the two extreme regimes, constitutive equations have been proposed based on kinetic theory for collisional rapid flows, and soil mechanics for slow plastic flows. However, the intermediate dense regime, where the granular material flows like a liquid, still lacks a unified view and has motivated many studies over the past decade. The main characteristics of granular liquids are: a yield criterion (a critical shear stress below which flow is not possible) and a complex dependence on shear rate when flowing. In this sense, granular matter shares similarities with classical visco-plastic fluids such as Bingham fluids. Here we propose a new constitutive relation for dense granular flows, inspired by this analogy and recent numerical and experimental work. We then test our three-dimensional (3D) model through experiments on granular flows on a pile between rough sidewalls, in which a complex 3D flow pattern develops. We show that, without any fitting parameter, the model gives quantitative predictions for the flow shape and velocity profiles. Our results support the idea that a simple visco-plastic approach can quantitatively capture granular flow properties, and could serve as a basic tool for modelling more complex flows in geophysical or industrial applications.Comment: http://www.nature.com/nature/journal/v441/n7094/abs/nature04801.htm

    Association of peripartum management and high maternal blood loss at cesarean delivery for placenta accreta spectrum (PAS) : A multinational database study

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    Introduction Placenta accreta spectrum (PAS) carries a high burden of adverse maternal outcomes, especially significant blood loss, which can be life-threatening. Different management strategies have been proposed but the association of clinical risk factors and surgical management options during cesarean delivery with high blood loss is not clear. Material and methods In this international multicenter study, 338 women with PAS undergoing cesarean delivery were included. Fourteen European and one non-European center (USA) provided cases treated retrospectively between 2008 and 2014 and prospectively from 2014 to 2019. Peripartum blood loss was estimated visually and/or by weighing and measuring of volume. Participants were grouped based on blood loss above or below the 75th percentile (>3500 ml) and the 90th percentile (>5500 ml). Results Placenta percreta was found in 58% of cases. Median blood loss was 2000 ml (range: 150-20 000 ml). Unplanned hysterectomy was associated with an increased risk of blood loss >3500 ml when compared with planned hysterectomy (adjusted OR [aOR] 3.7 [1.5-9.4], p = 0.01). Focal resection was associated with blood loss comparable to that of planned hysterectomy (crude OR 0.7 [0.2-2.1], p = 0.49). Blood loss >3500 ml was less common in patients undergoing successful conservative management (placenta left in situ, aOR 0.1 [0.0-0.6], p = 0.02) but was more common in patients who required delayed hysterectomy (aOR 6.5 [1.7-24.4], p = 0.001). Arterial occlusion methods (uterine or iliac artery ligation, embolization or intravascular balloons), application of uterotonic medication or tranexamic acid showed no significant effect on blood loss >3500 ml. Patients delivered by surgeons without experience in PAS were more likely to experience blood loss >3500 ml (aOR 3.0 [1.4-6.4], p = 0.01). Conclusions In pregnant women with PAS, the likelihood of blood loss >3500 ml was reduced in planned vs unplanned cesarean delivery, and when the surgery was performed by a specialist experienced in the management of PAS. This reinforces the necessity of delivery by an expert team. Conservative management was also associated with less blood loss, but only if successful. Therefore, careful patient selection is of great importance. Our study showed no consistent benefit of other adjunct measures such as arterial occlusion techniques, uterotonics or tranexamic acid.Peer reviewe

    Maternal and neonatal outcomes in planned versus emergency cesarean delivery for placenta accreta spectrum: A multinational database study

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    Introduction: Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). Material and methods: Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as "planned" when performed at a time and date to suit the team. All the remaining cases were classified as "emergency". Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. Results: In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P = .02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34+1 to 36+0 weeks and 19% at >36+0 weeks. Conclusions: Emergency delivery in centers of excellence did not increase blood loss, transfusion rates or maternal morbidity. The single greatest risk factor for emergency delivery was antenatal hemorrhage. When adequate expertise and resources are available, to defer delivery in women with no significant antenatal bleeding and no risk factors for pre-term birth until >36+0 weeks can be considered to improve fetal outcomes. Further studies are needed to investigate this fully

    Association of peripartum management and high maternal blood loss at cesarean delivery for placenta accreta spectrum (PAS): A multinational database study

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    Introduction: Placenta accreta spectrum (PAS) carries a high burden of adverse maternal outcomes, especially significant blood loss, which can be life-threatening. Different management strategies have been proposed but the association of clinical risk factors and surgical management options during cesarean delivery with high blood loss is not clear. Material and methods: In this international multicenter study, 338 women with PAS undergoing cesarean delivery were included. Fourteen European and one non-European center (USA) provided cases treated retrospectively between 2008 and 2014 and prospectively from 2014 to 2019. Peripartum blood loss was estimated visually and/or by weighing and measuring of volume. Participants were grouped based on blood loss above or below the 75th percentile (>3500 ml) and the 90th percentile (>5500 ml). Results: Placenta percreta was found in 58% of cases. Median blood loss was 2000 ml (range: 150-20 000 ml). Unplanned hysterectomy was associated with an increased risk of blood loss >3500 ml when compared with planned hysterectomy (adjusted OR [aOR] 3.7 [1.5-9.4], p = 0.01). Focal resection was associated with blood loss comparable to that of planned hysterectomy (crude OR 0.7 [0.2-2.1], p = 0.49). Blood loss >3500 ml was less common in patients undergoing successful conservative management (placenta left in situ, aOR 0.1 [0.0-0.6], p = 0.02) but was more common in patients who required delayed hysterectomy (aOR 6.5 [1.7-24.4], p = 0.001). Arterial occlusion methods (uterine or iliac artery ligation, embolization or intravascular balloons), application of uterotonic medication or tranexamic acid showed no significant effect on blood loss >3500 ml. Patients delivered by surgeons without experience in PAS were more likely to experience blood loss >3500 ml (aOR 3.0 [1.4-6.4], p = 0.01). Conclusions: In pregnant women with PAS, the likelihood of blood loss >3500 ml was reduced in planned vs unplanned cesarean delivery, and when the surgery was performed by a specialist experienced in the management of PAS. This reinforces the necessity of delivery by an expert team. Conservative management was also associated with less blood loss, but only if successful. Therefore, careful patient selection is of great importance. Our study showed no consistent benefit of other adjunct measures such as arterial occlusion techniques, uterotonics or tranexamic acid

    Developing a database for multicenter evaluation of placenta accreta spectrum

    Get PDF
    Studies of rare, but complex clinical conditions require multicenter cooperation. The International Society for Placenta accreta spectrum (IS-PAS) have established a secure web-based database to analyze pregnancies complicated by PAS. By repeated in-person meetings of the IS-PAS, a core dataset was established. Then, a custom-made, secure online database, capable of receiving strictly anonymized patient-related textual and imaging data and allowing statistical queries was designed, tested, amended and implemented. Between 2008 and 2019, 14 IS-PAS centers across Europe and one center in the USA contributed data for all their PAS cases, containing pregnancy data for a total of 442 pregnant women. Data were analyzed by a designated data analysis sub-group of the IS-PAS. Center characteristics are presented. Based on experiences with previous versions, our new online database now allows an all-encompassing data collection. It has shown its usefulness in the current analysis project

    CD44s and CD44v6 Expression in Head and Neck Epithelia

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    Background: CD44 splice variants are long-known as being associated with cell transformation. Recently, the standard form of CD44 (CD44s) was shown to be part of the signature of cancer stem cells (CSCs) in colon, breast, and in head and neck squamous cell carcinomas (HNSCC). This is somewhat in contradiction to previous reports on the expression of CD44s in HNSCC. The aim of the present study was to clarify the actual pattern of CD44 expression in head and neck epithelia. Methods: Expression of CD44s and CD44v6 was analysed by immunohistochemistry with specific antibodies in primary head and neck tissues. Scoring of all specimens followed a two-parameters system, which implemented percentages of positive cells and staining intensities from − to +++ (score = %×intensity; resulting max. score 300). In addition, cell surface expression of CD44s and CD44v6 was assessed in lymphocytes and HNSCC. Results: In normal epithelia CD44s and CD44v6 were expressed in 60–95% and 50–80% of cells and yielded mean scores with a standard error of a mean (SEM) of 249.5±14.5 and 198±11.13, respectively. In oral leukoplakia and in moderately differentiated carcinomas CD44s and CD44v6 levels were slightly increased (278.9±7.16 and 242±11.7; 291.8±5.88 and 287.3±6.88). Carcinomas in situ displayed unchanged levels of both proteins whereas poorly differentiated carcinomas consistently expressed diminished CD44s and CD44v6 levels. Lymphocytes and HNSCC lines strongly expressed CD44s but not CD44v6. Conclusion: CD44s and CD44v6 expression does not distinguish normal from benign or malignant epithelia of the head and neck. CD44s and CD44v6 were abundantly present in the great majority of cells in head and neck tissues, including carcinomas. Hence, the value of CD44s as a marker for the definition of a small subset of cells (i.e. less than 10%) representing head and neck cancer stem cells may need revision

    Biomarker counseling, disclosure of diagnosis and follow-up in patients with mild cognitive impairment:A European Alzheimer's Disease Consortium survey

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    Objectives: Mild cognitive impairment (MCI) is associated with an increased risk of further cognitive decline, partly depending on demographics and biomarker status. The aim of the present study was to survey the clinical practices of physicians in terms of biomarker counseling, management, and follow-up in European expert centers diagnosing patients with MCI. Methods: An online email survey was distributed to physicians affiliated with European Alzheimer's disease Consortium centers (Northern Europe: 10 centers; Eastern and Central Europe: 9 centers; and Southern Europe: 15 centers) with questions on attitudes toward biomarkers and biomarker counseling in MCI and dementia. This included postbiomarker counseling and the process of diagnostic disclosure of MCI, as well as treatment and follow-up in MCI. Results: The response rate for the survey was 80.9% (34 of 42 centers) across 20 countries. A large majority of physicians had access to biomarkers and found them useful. Pre- and postbiomarker counseling varied across centers, as did practices for referral to support groups and advice on preventive strategies. Less than half reported discussing driving and advance care planning with patients with MCI. Conclusions: The variability in clinical practices across centers calls for better biomarker counseling and better training to improve communication skills. Future initiatives should address the importance of communicating preventive strategies and advance planning

    The boron-oxygen core of borinate esters is responsible for the store-operated calcium entry potentiation ability

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    International audienceBACKGROUND: Store-Operated Calcium Entry (SOCE) is the major Ca2+ ion entry pathway in lymphocytes and is responsible of a severe combined immunodeficiency (SCID) when deficient. It has recently been observed or highlighted in other cell types such as myoblasts and neurons, suggesting a wider physiological role of this pathway. Whereas Orai1 protein is considered to be the channel allowing the SOCE in T cells, it is hypothesized that other proteins like TRPC could associate with Orai1 to form SOCE with different pharmacology and kinetics in other cell types. Unraveling SOCE cell functions requires specific effectors to be identified, just as dihydropyridines were crucial for the study of Ca2+ voltage-gated channels, or spider/snake toxins for other ion channel classes. To identify novel SOCE effectors, we analyzed the effects of 2-aminoethyl diphenylborinate (2-APB) and its analogues. 2-APB is a molecule known to both potentiate and inhibit T cell SOCE, but it is also an effector of TRP channels and endoplasmic reticulum Ca2+-ATPase. RESULTS: A structure-function analysis allowed to discover that the boron-oxygen core present in 2-APB and in the borinate ester analogues is absolutely required for the dual effects on SOCE. Indeed, a 2-APB analogue where the boron-oxygen core is replaced by a carbon-phosphorus core is devoid of potentiating capacity (while retaining inhibition capacity), highlighting the key role of the boron-oxygen core present in borinate esters for the potentiation function. However, dimesityl borinate ester, a 2-APB analogue with a terminal B-OH group showed an efficient inhibitory ability, without any potentiating capacity. The removal or addition of phenyl groups respectively decrease or increase the efficiency of the borinate esters to potentiate and inhibit the SOCE. mRNA expression revealed that Jurkat T cells mainly expressed Orai1, and were the more sensitive to 2-APB modulation of SOCE. CONCLUSIONS: This study allows the discovery of new boron-oxygen core containing compounds with the same ability as 2-APB to both potentiate and inhibit the SOCE of different leukocyte cell lines. These compounds could represent new tools to characterize the different types of SOCE and the first step in the development of new immunomodulators

    Identification of a Novel Signaling Pathway and Its Relevance for GluA1 Recycling

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    We previously showed that the serum- and glucocorticoid-inducible kinase 3 (SGK3) increases the AMPA-type glutamate receptor GluA1 protein in the plasma membrane. The activation of AMPA receptors by NMDA-type glutamate receptors eventually leads to postsynaptic neuronal plasticity. Here, we show that SGK3 mRNA is upregulated in the hippocampus of new-born wild type Wistar rats after NMDA receptor activation. We further demonstrate in the Xenopus oocyte expression system that delivery of GluA1 protein to the plasma membrane depends on the small GTPase RAB11. This RAB-dependent GluA1 trafficking requires phosphorylation and activation of phosphoinositol-3-phosphate-5-kinase (PIKfyve) and the generation of PI(3,5)P2. In line with this mechanism we could show PIKfyve mRNA expression in the hippocampus of wild type C57/BL6 mice and phosphorylation of PIKfyve by SGK3. Incubation of hippocampal slices with the PIKfyve inhibitor YM201636 revealed reduced CA1 basal synaptic activity. Furthermore, treatment of primary hippocampal neurons with YM201636 altered the GluA1 expression pattern towards reduced synaptic expression of GluA1. Our findings demonstrate for the first time an involvement of PIKfyve and PI(3,5)P2 in NMDA receptor-triggered synaptic GluA1 trafficking. This new regulatory pathway of GluA1 may contribute to synaptic plasticity and memory
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