Interaction of Saccharomyces boulardii with Salmonella enterica Serovar Typhimurium Protects Mice and Modifies T84 Cell Response to the Infection

BACKGROUND: Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-kappaB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we reported that S. boulardii (Sb) protected mice from Salmonella enterica serovar Typhimurium (ST)-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-kappaB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. CONCLUSIONS: Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella

Saccharomyces boulardii Interferes with Enterohemorrhagic Escherichia coli-Induced Signaling Pathways in T84 Cells

Enterohemorrhagic Escherichia coli (EHEC) infections are associated with the modification of tight-junction permeability and synthesis of proinflammatory cytokine interleukin-8 (IL-8). In a previous study, it was demonstrated that EHEC-induced IL-8 secretion is due to the involvement of the mitogen-activated protein kinase (MAPK), AP-1, and NF-κB pathways. In this study, we investigated the effect of the yeast Saccharomyces boulardii on EHEC infection in T84 cells. For this purpose, cells were (i) incubated with bacteria and yeast at the same time or (ii) incubated overnight with yeast cells that were maintained during infection or eliminated by several washes before infection. Coincubation is sufficient to maintain the transmonolayer electrical resistance (TER) of EHEC-infected cells, whereas the preincubation of cells with the yeast without elimination of the yeast during infection is necessary to significantly decrease IL-8 secretion. We thus analyzed the mechanisms of S. boulardii action. We showed that S. boulardii has no effect on EHEC growth or on EHEC adhesion. Kinetics studies revealed that EHEC-induced myosin light chain (MLC) phosphorylation precedes the decrease of TER. ML-7, an MLC kinase inhibitor, abolishes the EHEC-induced MLC phosphorylation and decrease of TER. Studies show that S. boulardii also abolishes EHEC-induced MLC phosphorylation. We demonstrated that the preincubation of cells with S. boulardii without washes before EHEC infection inhibits NF-κB DNA binding activity, phosphorylation and degradation of IκB-α, and activation of the three members of a MAPK group (extracellular signal-regulated protein kinases 1 and 2, p38, and c-jun N-terminal kinase). These findings demonstrate that S. boulardii exerts a preventive effect on EHEC infection by (i) interfering with one of the transduction pathways implicated in the control of tight-junction structure and (ii) decreasing IL-8 proinflammatory secretion via inhibition of the NF-κB and MAPK signaling pathways in infected T84 cells

Adherence to treatment in systemic lupus erythematosus patients

International audienceAdherence is defined as "the extent to which a person's behaviour coincides with medical or health advice." Poor adherence to therapeutic regimens is a common and expensive problem in patients with chronic diseases including systemic lupus erythematosus (SLE) and is associated with a higher risk of flares, morbidity, hospitalisations and poor renal outcome. Non-adherence to the treatment is multifactorial for most patients and varies according to unintentional or intentional patterns. The rates of non-adherence in SLE patients range from 3% to 76% depending on the assessment methods, which are all subject to limitations. Indeed, poor adherence to therapeutic regimens is difficult to evaluate. Two studies have shown that undetectable blood hydroxychloroquine (HCQ) concentration may be a simple, objective and reliable marker of non-adherence in SLE patients. The accurate diagnosis of non-adherence may prevent one from incorrectly interpreting disease manifestations as a lack of response. It may then avoid an unnecessary or even dangerous treatment escalation

Frequency and dynamics of leukemia-initiating cells during short-term ex vivo culture informs outcomes in acute myeloid leukemia patients

Acute myeloid leukemia (AML) is sustained by a subpopulation of rare leukemia-initiating cells (LICs), detectable by their capacity to self-renew and generate non-LICs in vivo. The xenograft assay captures functional properties of LICs that have clinical prognostic value, but the long duration of xenotransplantation has hampered its implementation in the clinic. Here, we describe an ex vivo co-culture system in which the frequency of leukemic long-term culture-initiating cells (L-LTC-ICs) can be used as a reliable read-out of LIC activity over one week. We analyzed 92 AML patients classified as having a poor, intermediate, or favorable prognosis at time of diagnosis. Ex vivo limiting dilution analyses demonstrated that the frequency of L-LTC-ICs was 5-7 times higher in intermediate and poor prognosis samples compared with favorable samples after five weeks of co-culture with MS-5 stromal cells. To simplify and shorten this test, we defined a fluorescence dilution factor (FDF) as the ratio of the median fluorescence intensity, based on CFSE staining, before and after one week of co-culture. L-LTC-IC proliferation, monitored over one week, was strongly correlated to L-LTC-IC frequency. A higher FDF was evident in poor prognosis AMLs or in samples capable of engrafting NSG mice compared with favorable prognosis AMLs or non-engrafters. Notably, the FDF could classify intermediate prognosis patients with normal karyotype into two groups differing in overall survival. This non-genetic and non-in vivo approach represents a new clinically relevant tool for rapidly and reliably predicting AML patient outcome

Intrauterine fetal deaths related to antiphospholipid syndrome: a descriptive study of 65 women

International audienceObjectiveAlthough one of the three obstetric manifestations of antiphospholipid syndrome (APS) is intrauterine fetal death (IUFD), little is known about it in this context. We report the first large series of patients with APS and IUFD.MethodsWe retrospectively analyzed the history and clinical data of women at four French hospitals. All had (1) APS diagnosis (Sydney criteria) and (2) IUFD at or after 10 weeks of gestation (weeks) between 2000 and 2016.ResultsThe study included 65 women. Their median age at the index IUFD was 29 years (IQR 26–33); 38 (58%) were primigravidas. The index IUFD was the first APS clinical manifestation in 48 women (74%). Overall, 35% had a triple-positive antibody profile.IUFD occurred at a median gestational age of 24 weeks (IQR 18–27) and was associated with maternal obstetric complications in 16 women (25%), namely, preeclampsia (n = 12), hemolysis, elevated liver enzymes, and low platelet syndrome (HELLP) (n = 6), and/or placental abruption (n = 5). Half of the 50 women with available data had a small-for-gestational-age fetus.Overall, including during the follow-up period of 4 years (IQR 2–9), 28 women (43%) had at least one thrombosis, and 29% were diagnosed with systemic lupus erythematosus (SLE). Ultimately, 54 women (83%) had at least one live birth. Only one woman had three consecutive early miscarriages.ConclusionIUFD was most often the inaugural sign of APS. Of the APS classification criteria, IUFD, preeclampsia, and thromboses were common in this cohort, while the “3 consecutive early miscarriages” criterion was met only once. With treatment, most of the women successfully had at least one live birth

Intrauterine fetal deaths related to antiphospholipid syndrome: a descriptive study of 65 women

International audienceObjectiveAlthough one of the three obstetric manifestations of antiphospholipid syndrome (APS) is intrauterine fetal death (IUFD), little is known about it in this context. We report the first large series of patients with APS and IUFD.MethodsWe retrospectively analyzed the history and clinical data of women at four French hospitals. All had (1) APS diagnosis (Sydney criteria) and (2) IUFD at or after 10 weeks of gestation (weeks) between 2000 and 2016.ResultsThe study included 65 women. Their median age at the index IUFD was 29 years (IQR 26–33); 38 (58%) were primigravidas. The index IUFD was the first APS clinical manifestation in 48 women (74%). Overall, 35% had a triple-positive antibody profile.IUFD occurred at a median gestational age of 24 weeks (IQR 18–27) and was associated with maternal obstetric complications in 16 women (25%), namely, preeclampsia (n = 12), hemolysis, elevated liver enzymes, and low platelet syndrome (HELLP) (n = 6), and/or placental abruption (n = 5). Half of the 50 women with available data had a small-for-gestational-age fetus.Overall, including during the follow-up period of 4 years (IQR 2–9), 28 women (43%) had at least one thrombosis, and 29% were diagnosed with systemic lupus erythematosus (SLE). Ultimately, 54 women (83%) had at least one live birth. Only one woman had three consecutive early miscarriages.ConclusionIUFD was most often the inaugural sign of APS. Of the APS classification criteria, IUFD, preeclampsia, and thromboses were common in this cohort, while the “3 consecutive early miscarriages” criterion was met only once. With treatment, most of the women successfully had at least one live birth

Hemolysis indexes for biochemical tests and immunoassays on Roche analyzers: Determination of allowable interference limits according to different calculation methods

<div><p></p><p><b><i>Objectives.</i></b> To determine the hemolysis interference on biochemical tests and immunoassays performed on Roche Diagnostics analyzers, according to different maximum allowable limits. <b><i>Design and methods.</i></b> Heparinized plasma and serum pools, free of interferences, were overloaded by increasing amounts of a hemoglobin-titrated hemolysate. This interference was evaluated for 45 analytes using Modular^® and Cobas^® analyzers. For each parameter, the hemolysis index (HI) corresponding to the traditional ± 10% change of concentrations from baseline (± 10%Δ) was determined, as well as those corresponding to the analytical change limit (ACL), and to the reference change value (RCV). Then, the relative frequencies distribution (% RFD) of hemolyzed tests performed in a hospital laboratory over a 25-day period were established for each HI as allowable limit. <b><i>Results.</i></b> Considering the ± 10%Δ, the analyte concentrations enhanced by hemolysis were: Lactate dehydrogenase (LDH), aspartate aminotransferase (AST), folate, potassium, creatine kinase, phosphorus, iron, alanine aminotransferase, lipase, magnesium and triglycerides, decreasingly. The analyte concentrations decreased by hemolysis were: Haptoglobin, high-sensitive troponin T and alkaline phosphatase. Over the 25-day period, the % RFD of tests impacted more than 10%Δ by hemolysis were < 7% for LDH; < 5% for AST, folates and iron; and < 1% for the other analytes. Considering the ACL, HI were lower, giving % RFD substantially increased for many analytes, whereas only four analytes remain sensitive to hemolysis when considering RCV. <b><i>Conclusion.</i></b> This study proposes new HI based on different allowable limits, and can therefore serve as a starting point for future harmonization of hemolysis interference evaluation needed in routine laboratory practice.</p></div

Intrauterine fetal deaths related to antiphospholipid syndrome: a descriptive study of 65 women

International audienceObjectiveAlthough one of the three obstetric manifestations of antiphospholipid syndrome (APS) is intrauterine fetal death (IUFD), little is known about it in this context. We report the first large series of patients with APS and IUFD.MethodsWe retrospectively analyzed the history and clinical data of women at four French hospitals. All had (1) APS diagnosis (Sydney criteria) and (2) IUFD at or after 10 weeks of gestation (weeks) between 2000 and 2016.ResultsThe study included 65 women. Their median age at the index IUFD was 29 years (IQR 26–33); 38 (58%) were primigravidas. The index IUFD was the first APS clinical manifestation in 48 women (74%). Overall, 35% had a triple-positive antibody profile.IUFD occurred at a median gestational age of 24 weeks (IQR 18–27) and was associated with maternal obstetric complications in 16 women (25%), namely, preeclampsia (n = 12), hemolysis, elevated liver enzymes, and low platelet syndrome (HELLP) (n = 6), and/or placental abruption (n = 5). Half of the 50 women with available data had a small-for-gestational-age fetus.Overall, including during the follow-up period of 4 years (IQR 2–9), 28 women (43%) had at least one thrombosis, and 29% were diagnosed with systemic lupus erythematosus (SLE). Ultimately, 54 women (83%) had at least one live birth. Only one woman had three consecutive early miscarriages.ConclusionIUFD was most often the inaugural sign of APS. Of the APS classification criteria, IUFD, preeclampsia, and thromboses were common in this cohort, while the “3 consecutive early miscarriages” criterion was met only once. With treatment, most of the women successfully had at least one live birth