374 research outputs found

    Interleukin-1 receptor antagonist gene (IL-1RN) polymorphism is a predictive factor of clinical pregnancy after IVF

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    BACKGROUND Only 25% of IVF transfer cycles lead to a clinical pregnancy, calling for continued technical progress but also more in depth analysis of patients' individual characteristics. The interleukin-1 (IL-1) system and matrix metalloproteinases (MMPs) are strongly implicated in embryo implantation. The genes coding for IL-1Ra (gene symbol IL-1RN), IL-1Ī², MMP2 and MMP9 bear functional polymorphisms. We analysed the maternal genetic profile at these polymorphic sites in IVF patients, to determine possible correlations with IVF outcome. METHODS One hundred and sixty women undergoing an IVF cycle were enrolled and a buccal smear was obtained. The presence of IL-1RN variable number of tandem repeats and IL-1B + 3953, MMP2-1306 and MMP9-1562 single nucleotide substitutions were determined. Patients were divided into pregnancy failures (119), biochemical pregnancies (8) and clinical pregnancies (33). RESULTS There was a 40% decrease in IL-1RN*2 allele frequency (P = 0.024) and a 45% decrease in IL-1RN*2 carrier status in the clinical pregnancy group as compared to the pregnancy failure group (P = 0.017). This decrease was still statistically significant after a multivariate logistic regression analysis. The likelihood of a clinical pregnancy was decreased accordingly in IL-1RN*2 carriers: odds ratio = 0.349, 95% confidence interval = 0.2-0.8, P = 0.017. The IL-1B, MMP2 and MMP9 polymorphisms showed no correlation with IVF outcome. CONCLUSIONS IL-1RN*2 allele carriage is associated with a poor prognosis of achieving a pregnancy after IV

    Tenascin-C inactivation impacts lung structure and function beyond lung development

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    Tenascin-C (TNC) is an extracellular matrix protein expressed at high levels during lung organogenesis. Later, TNC is only transiently de novo expressed to orchestrate tissue repair in pathological situations. We previously showed that TNC inactivation affects lung development and thus evaluated here the implications on lung function in newborn/adult mice. Respiratory function parameters were measured in anesthetized and mechanically ventilated wild-type (WT) and TNC-deficient mice at 5 (P5) and 90 (P90) days of age under basal conditions, as well as following high tidal volume (HTV) ventilation. At P5, TNC-deficient mice showed an increased static compliance (Cst) and inspiratory capacity (IC) relative to WT at baseline and throughout HTV. At P90, however, Cst and IC were only elevated at baseline. Control non-ventilated newborn and adult TNC-deficient mice showed similar lung morphology, but less alpha smooth muscle actin (Ī±-SMA) around small airways. SMAā€‰+ā€‰cells were decreased by 50% in adult TNC-deficient lungs and collagen layer thickened around small airways. Increased surfactant protein C (SP-C) and altered TGFĪ² and TLR4 signaling pathways were also detected. Thus, TNC inactivation-related defects during organogenesis led to persisting functional impairment in adulthood. This might be of interest in the context of pulmonary diseases with thickened airway smooth muscle layer or ventilation heterogeneity, like asthma and COPD

    Dysregulated monocyte-derived macrophage response to Group B Streptococcus in newborns.

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    INTRODUCTION Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading pathogen of neonatal sepsis. The host-pathogen interactions underlying the progression to life-threatening infection in newborns are incompletely understood. Macrophages are first line in host defenses against GBS, contributing to the initiation, amplification, and termination of immune responses. The goal of this study was to compare the response of newborn and adult monocyte-derived macrophages (MDMs) to GBS. METHODS Monocytes from umbilical cord blood of healthy term newborns and from peripheral blood of healthy adult subjects were cultured with M-CSF to induce MDMs. M-CSF-MDMs, GM-CSF- and IFNĪ³-activated MDMs were exposed to GBS COH1, a reference strain for neonatal sepsis. RESULTS GBS induced a greater release of IL-1Ī², IL-6, IL-10, IL-12p70 and IL-23 in newborn compared to adult MDMs, while IL-18, IL-21, IL-22, TNF, RANTES/CCL5, MCP-1/CCL2 and IL-8/CXCL8 were released at similar levels. MDM responses to GBS were strongly influenced by conditions of activation and were distinct from those to synthetic bacterial lipopeptides and lipopolysaccharides. Under similar conditions of opsonization, newborn MDMs phagocytosed and killed GBS as efficiently as adult MDMs. DISCUSSION Altogether, the production of excessive levels of Th1- (IL-12p70), Th17-related (IL-1Ī², IL-6, IL-23) and anti-inflammatory (IL-10) cytokines is consistent with a dysregulated response to GBS in newborns. The high responsiveness of newborn MDMs may play a role in the progression of GBS infection in newborns, possibly contributing to the development of life-threatening organ dysfunction

    Translational potential of a mouse in vitro bioassay in predicting gastrointestinal adverse drug reactions in Phase I clinical trials.

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    Motility-related gastrointestinal (GI) adverse drug reactions (GADRs) such as diarrhea and constipation are a common and deleterious feature associated with drug development. Novel biomarkers of GI function are therefore required to aid decision making on the GI liability of compounds in development

    Long-term exposure of mouse pancreatic islets to oleate or palmitate results in reduced glucose-induced somatostatin and oversecretion of glucagon

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    AIMS/HYPOTHESIS: Long-term exposure to NEFAs leads to inhibition of glucose-induced insulin secretion. We tested whether the release of somatostatin and glucagon, the two other major islet hormones, is also affected. METHODS: Mouse pancreatic islets were cultured for 72 h at 4.5 or 15 mmol/l glucose with or without 0.5 mmol/l oleate or palmitate. The release of glucagon and somatostatin during subsequent 1 h incubations at 1 or 20 mmol/l glucose as well as the islet content of the two hormones were determined. Lipid-induced changes in islet cell ultrastructure were assessed by electron microscopy. RESULTS: Culture at 15 mmol/l glucose increased islet glucagon content by approximately 50% relative to that observed following culture at 4.5 mmol/l glucose. Inclusion of oleate or palmitate reduced islet glucagon content by 25% (at 4.5 mmol/l glucose) to 50% (at 15 mmol/l glucose). Long-term exposure to the NEFA increased glucagon secretion at 1 mmol/l glucose by 50% (when islets had been cultured at 15 mmol/l glucose) to 100% (with 4.5 mmol/l glucose in the culture medium) and abolished the inhibitory effect of 20 mmol/l glucose on glucagon secretion. Somatostatin content was unaffected by glucose and lipids, but glucose-induced somatostatin secretion was reduced by approximately 50% following long-term exposure to either of the NEFA, regardless of whether the culture medium contained 4.5 or 15 mmol/l glucose. Ultrastructural evidence of lipid deposition was seen in <10% of non-beta cells but in >80% of the beta cells. CONCLUSIONS/INTERPRETATION: Long-term exposure to high glucose and/or NEFA affects the release of somatostatin and glucagon. The effects on glucagon secretion are very pronounced and in type 2 diabetes in vivo may aggravate the hyperglycaemic effects due to lack of insulin

    Neonatal steroids induce a down-regulation of tenascin-C and elastin and cause a deceleration of the first phase and an acceleration of the second phase of lung alveolarization

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    Pre- and postnatal corticosteroids are often used in perinatal medicine to improve pulmonary function in preterm infants. To mimic this clinical situation, newborn rats were treated systemically with dexamethasone (Dex), 0.1-0.01mg/kg/day on days P1-P4. We hypothesized that postnatal Dex may have an impact on alveolarization by interfering with extracellular matrix proteins and cellular differentiation. Morphological alterations were observed on 3D images obtained by high-resolution synchrotron radiation X-ray tomographic microscopy. Alveolarization was quantified stereologically by estimating the formation of new septa between days P4 and P60. The parenchymal expression of tenascin-C (TNC), smooth muscle actin (SMA), and elastin was measured by immunofluorescence and gene expression for TNC by qRT-PCR. After Dex treatment, the first phase of alveolarization was significantly delayed between days P6 and P10, whereas the second phase was accelerated. Elastin and SMA expressions were delayed by Dex treatment, whereas TNC expression was delayed and prolonged. A short course of neonatal steroids impairs the first phase of alveolarization, most likely by altering the TNC and elastin expression. Due to an overshooting catch-up during the second phase of alveolarization, the differences disappear when the animals reach adulthood

    Advantages of dynamic ā€œclosed loopā€ stable isotope flux phenotyping over static ā€œopen loopā€ clamps in detecting silent genetic and dietary phenotypes

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    In vivo insulin sensitivity can be assessed using ā€œopen loopā€ clamp or ā€œclosed loopā€ methods. Open loop clamp methods are static, and fix plasma glucose independently from plasma insulin. Closed loop methods are dynamic, and assess glucose disposal in response to a stable isotope labeled glucose tolerance test. Using PPARĪ±āˆ’/āˆ’ mice, open and closed loop assessments of insulin sensitivity/glucose disposal were compared. Indirect calorimetry done for the assessment of diurnal substrate utilization/metabolic flexibility showed that chow fed PPARĪ±āˆ’/āˆ’ mice had increased glucose utilization during the light (starved) cycle. Euglycemic clamps showed no differences in insulin stimulated glucose disposal, whether for chow or high fat diets, but did show differences in basal glucose clearance for chow fed PPARĪ±āˆ’/āˆ’ versus SV129J-wt mice. In contrast, the dynamic stable isotope labeled glucose tolerance tests reveal enhanced glucose disposal for PPARĪ±āˆ’/āˆ’ versus SV129J-wt, for chow and high fat diets. Area under the curve for plasma labeled and unlabeled glucose for PPARĪ±āˆ’/āˆ’ was ā‰ˆ1.7-fold lower, PĀ <Ā 0.01 during the stable isotope labeled glucose tolerance test for both diets. Area under the curve for plasma insulin was 5-fold less for the chow fed SV129J-wt (PĀ <Ā 0.01) but showed no difference on a high fat diet (0.30Ā Ā±Ā 0.1 for SV129J-wt vs. 0.13Ā Ā±Ā 0.10 for PPARĪ±āˆ’/āˆ’, PĀ =Ā 0.28). This study demonstrates that dynamic stable isotope labeled glucose tolerance test can assess ā€œsilentā€ metabolic phenotypes, not detectable by the static, ā€œopen loopā€, euglycemic or hyperglycemic clamps. Both open loop and closed loop methods may describe different aspects of metabolic inflexibility and insulin sensitivity

    Analysis of Intracellular State Based on Controlled 3D Nanostructures Mediated Surface Enhanced Raman Scattering

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    Near-infrared surface-enhanced Raman spectroscopy (SERS) is a powerful technique for analyzing the chemical composition within a single living cell at unprecedented resolution. However, current SERS methods employing uncontrollable colloidal metal particles or non-uniformly distributed metal particles on a substrate as SERS-active sites show relatively low reliability and reproducibility. Here, we report a highly-ordered SERS-active surface that is provided by a gold nano-dots array based on thermal evaporation of gold onto an ITO surface through a nanoporous alumina mask. This new combined technique showed a broader distribution of hot spots and a higher signal-to-noise ratio than current SERS techniques due to the highly reproducible and uniform geometrical structures over a large area. This SERS-active surface was applied as cell culture system to study living cells in situ within their culture environment without any external preparation processes. We applied this newly developed method to cell-based research to differentiate cell lines, cells at different cell cycle stages, and live/dead cells. The enhanced Raman signals achieved from each cell, which represent the changes in biochemical compositions, enabled differentiation of each state and the conditions of the cells. This SERS technique employing a tightly controlled nanostructure array can potentially be applied to single cell analysis, early cancer diagnosis and cell physiology research

    Determination of composition and structure of spongy bone tissue in human head of femur by Raman spectral mapping

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    Biomechanical properties of bone depend on the composition and organization of collagen fibers. In this study, Raman microspectroscopy was employed to determine the content of mineral and organic constituents and orientation of collagen fibers in spongy bone in the human head of femur at the microstructural level. Changes in composition and structure of trabecula were illustrated using Raman spectral mapping. The polarized Raman spectra permit separate analysis of local variations in orientation and composition. The ratios of Ī½2PO43āˆ’/Amide III, Ī½4PO43āˆ’/Amide III and Ī½1CO32āˆ’/Ī½2PO43āˆ’ are used to describe relative amounts of spongy bone components. The Ī½1PO43āˆ’/Amide I ratio is quite susceptible to orientation effect and brings information on collagen fibers orientation. The results presented illustrate the versatility of the Raman method in the study of bone tissue. The study permits better understanding of bone physiology and evaluation of the biomechanical properties of bone
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