Stability of Relativistic Matter with Magnetic Fields for Nuclear Charges up to the Critical Value

We give a proof of stability of relativistic matter with magnetic fields all the way up to the critical value of the nuclear charge $Z\alpha=2/\pi$.Comment: LaTeX2e, 12 page

Endocytosis and intracellular processing of platelet microparticles by brain endothelial cells

Platelet-derived microparticles (PMP) bind and modify the phenotype of many cell types including endothelial cells. Recently, we showed that PMP were internalized by human brain endothelial cells (HBEC). Here we intend to better characterize the internalization mechanisms of PMP and their intracellular fate. Confocal microscopy analysis of PKH67-labelled PMP distribution in HBEC showed PMP in early endosome antigen 1 positive endosomes and in LysoTracker-labelled lysosomes, confirming a role for endocytosis in PMP internalization. No fusion of calcein-loaded PMP with HBEC membranes was observed. Quantification of PMP endocytosis using flow cytometry revealed that it was partially inhibited by trypsin digestion of PMP surface proteins and by extracellular Ca2+ chelation by EDTA, suggesting a partial role for receptor-mediated endocytosis in PMP uptake. This endocytosis was independent of endothelial receptors such as intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 and was not increased by tumour necrosis factor stimulation of HBEC. Platelet-derived microparticle internalization was dramatically increased in the presence of decomplemented serum, suggesting a role for PMP opsonin-dependent phagocytosis. Platelet-derived microparticle uptake was greatly diminished by treatment of HBEC with cytochalasin D, an inhibitor of microfilament formation required for both phagocytosis and macropinocytosis, with methyl-β-cyclodextrin that depletes membrane cholesterol needed for macropinocytosis and with amiloride that inhibits the Na+/H+ exchanger involved in macropinocytosis. In conclusion, PMP are taken up by active endocytosis in HBEC, involving mechanisms consistent with both phagocytosis and macropinocytosis. These findings identify new processes by which PMP could modify endothelial cell phenotype and functions. © 2011 The Authors. Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd

Recombinant gamma interferon provokes resistance of human breast cancer cells to spontaneous and IL-2 activated non-MHC restricted cytotoxicity.

Natural and lymphokine activated killer cells (NK and LAK) are believed to play an important role in the control of tumour progression and metastasis. Their specific receptors on tumours cells are still unknown. Several studies suggest that these cells recognise and eliminate abnormal cells with deleted or reduced expression of MHC class I molecules. Previous reports suggest that interferons (IFN), by increasing MHC class I expression on target cells, induce resistance to killing by NK cells. We investigated the role of MHC molecule expression by two human breast cancer cell lines T47D and ZR75-1 in their susceptibility to NK and LAK cells. These two cell lines spontaneously express low levels of HLA class I antigens but no HLA class II molecules. After IFN-gamma treatment they both overexpressed MHC class I and de novo expressed class II molecules as detected by flow cytometry, quantified by a radioimmunoassay and analysed by two-dimensional gel electrophoresis. Opposed to untreated cells these IFN-gamma treated cells were resistant to NK and LAK lysis. Furthermore, preincubation of IFN-gamma treated breast cancer cells with F(ab')2 fragments of monoclonal antibodies to HLA class I and HLA class II molecules was unable to restore lysis. In contrast, several complete monoclonal antibodies including anti-HLA class I and HLA class II induced the lysis of target cells whether or not they had been treated by IFN-gamma. The therapeutic use of monoclonal antibodies directed against antigens expressed on tumour cells (ADCC) in conjunction with interferon therapy should be discussed in lymphokine-based strategies for treatment of cancer patients

An optimization procedure of the start-up of Combined Cycle Power Plants

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HDL Interfere with the Binding of T Cell Microparticles to Human Monocytes to Inhibit Pro-Inflammatory Cytokine Production

BACKGROUND: Direct cellular contact with stimulated T cells is a potent mechanism that induces cytokine production in human monocytes in the absence of an infectious agent. This mechanism is likely to be relevant to T cell-mediated inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. Microparticles (MP) generated by stimulated T cells (MPT) display similar monocyte activating ability to whole T cells, isolated T cell membranes, or solubilized T cell membranes. We previously demonstrated that high-density lipoproteins (HDL) inhibited T cell contact- and MPT-induced production of IL-1beta but not of its natural inhibitor, the secreted form of IL-1 receptor antagonist (sIL-1Ra). METHODOLOGY/PRINCIPAL FINDINGS: Labeled MPT were used to assess their interaction with monocytes and T lymphocytes by flow cytometry. Similarly, interactions of labeled HDL with monocytes and MPT were assessed by flow cytometry. In parallel, the MPT-induction of IL-1beta and sIL-1Ra production in human monocytes and the effect of HDL were assessed in cell cultures. The results show that MPT, but not MP generated by activated endothelial cells, bond monocytes to trigger cytokine production. MPT did not bind T cells. The inhibition of IL-1beta production by HDL correlated with the inhibition of MPT binding to monocytes. HDL interacted with MPT rather than with monocytes suggesting that they bound the activating factor(s) of T cell surface. Furthermore, prototypical pro-inflammatory cytokines and chemokines such as TNF, IL-6, IL-8, CCL3 and CCL4 displayed a pattern of production induced by MPT and inhibition by HDL similar to IL-1beta, whereas the production of CCL2, like that of sIL-1Ra, was not inhibited by HDL. CONCLUSIONS/SIGNIFICANCE: HDL inhibit both MPT binding to monocytes and the MPT-induced production of some but not all cytokines, shedding new light on the mechanism by which HDL display their anti-inflammatory functions

Tests at 2K of the beta 0.35 spoke cryomodule prototype with the MTCA.4-based Low Level RF system prototype for the MYRRHA R&D

Within the framework of the first phase of MYRRHA (Multi-purpose hYbrid Research Reactor for High-tech Applications) project, called MINERVA, IJCLab was in charge of a fully equipped Spoke cryomodule prototype development, tested at 2K. It integrates two superconducting single spoke cavities, the RF power couplers and the Cold Tuning Systems associated. On the control side, a MTCA.4-based Low Level Radio Frequency (LLRF) system prototype and the Software/EPICS developments has been realized by IJCLab and the SCK CEN in collaboration with the company IOxOS Technologies. The final version of the global system and the results of the tests at 2K will show with some perspectives.Comment: Poster pr\'esent\'e au LLRF Workshop 2023 (LLRF2023, arXiv : 2310.03199

An overview of the cutaneous porphyrias

This is an overview of the cutaneous porphyrias. It is a narrative review based on the published literature and my personal experience; it is not based on a formal systematic search of the literature. The cutaneous porphyrias are a diverse group of conditions due to inherited or acquired enzyme defects in the porphyrin–haem biosynthetic pathway. All the cutaneous porphyrias can have (either as a consequence of the porphyria or as part of the cause of the porphyria) involvement of other organs as well as the skin. The single commonest cutaneous porphyria in most parts of the world is acquired porphyria cutanea tarda, which is usually due to chronic liver disease and liver iron overload. The next most common cutaneous porphyria, erythropoietic protoporphyria, is an inherited disorder in which the accumulation of bile-excreted protoporphyrin can cause gallstones and, rarely, liver disease. Some of the porphyrias that cause blistering (usually bullae) and fragility (clinically and histologically identical to porphyria cutanea tarda) can also be associated with acute neurovisceral porphyria attacks, particularly variegate porphyria and hereditary coproporphyria. Management of porphyria cutanea tarda mainly consists of visible-light photoprotection measures while awaiting the effects of treating the underlying liver disease (if possible) and treatments to reduce serum iron and porphyrin levels. In erythropoietic protoporphyria, the underlying cause can be resolved only with a bone marrow transplant (which is rarely justifiable in this condition), so management consists particularly of visible-light photoprotection and, in some countries, narrowband ultraviolet B phototherapy. Afamelanotide is a promising and newly available treatment for erythropoietic protoporphyria and has been approved in Europe since 2014

Molecular biology of breast cancer metastasis: Inflammatory breast cancer: clinical syndrome and molecular determinants

Inflammatory breast cancer (IBC) is an aggressive form of locally advanced breast cancer (LABC) that effects approximately 5% of women with breast cancer annually in the USA. It is a clinically and pathologically distinct form of LABC that is particularly fast growing, invasive, and angiogenic. Nearly all women have lymph node involvement at the time of diagnosis, and approximately 36% have gross distant metastases. Despite recent advances in multimodality treatments, the prognosis of patients with IBC is poor, with a median disease-free survival of less than 2.5 years. Recent work on the genetic determinants that underlie the IBC phenotype has led to the identification of genes that are involved in the development and progression of this disease. This work has been aided by the establishment of primary human cell lines and animal models. These advances suggest novel targets for future interventions in the diagnosis and treatment of IBC

Platelets Alter Gene Expression Profile in Human Brain Endothelial Cells in an In Vitro Model of Cerebral Malaria

Platelet adhesion to the brain microvasculature has been associated with cerebral malaria (CM) in humans, suggesting that platelets play a role in the pathogenesis of this syndrome. In vitro co-cultures have shown that platelets can act as a bridge between Plasmodium falciparum-infected red blood cells (pRBC) and human brain microvascular endothelial cells (HBEC) and potentiate HBEC apoptosis. Using cDNA microarray technology, we analyzed transcriptional changes of HBEC in response to platelets in the presence or the absence of tumor necrosis factor (TNF) and pRBC, which have been reported to alter gene expression in endothelial cells. Using a rigorous statistical approach with multiple test corrections, we showed a significant effect of platelets on gene expression in HBEC. We also detected a strong effect of TNF, whereas there was no transcriptional change induced specifically by pRBC. Nevertheless, a global ANOVA and a two-way ANOVA suggested that pRBC acted in interaction with platelets and TNF to alter gene expression in HBEC. The expression of selected genes was validated by RT-qPCR. The analysis of gene functional annotation indicated that platelets induce the expression of genes involved in inflammation and apoptosis, such as genes involved in chemokine-, TREM1-, cytokine-, IL10-, TGFβ-, death-receptor-, and apoptosis-signaling. Overall, our results support the hypothesis that platelets play a pathogenic role in CM

Update on inflammatory breast cancer

Inflammatory breast cancer (IBC) is both the least frequent and the most severe form of epithelial breast cancer. The diagnosis is based on clinical inflammatory signs and is reinforced by pathological findings. Significant progress has been made in the management of IBC in the past 20 years. Yet survival among IBC patients is still only one-half that among patients with non-IBC. Identification of the molecular determinants of IBC would probably lead to more specific treatments and to improved survival. In the present article we review recent advances in the molecular pathogenesis of IBC. A more comprehensive view will probably be obtained by pan-genomic analysis of human IBC samples, and by functional in vitro and in vivo assays. These approaches may offer better patient outcome in the near future