The new magnetic diagnostics in the WEST tokamak.

The WEST tokamak consists of a major upgrade of the superconducting medium size tokamak Tore Supra aiming at testing ITER divertor components. Such modification has required rebuilding a full set of magnetic diagnostics. The project was started in 2013 and completed in 2016. The diagnostic consists of a set of 469 sensors (421 pick-up coils, 36 flux loops, and 12 Rogowski coils) installed in the WEST vacuum vessel. New analog integrators have been developed in order to obtain the magnetic field and flux from the raw signal of the sensors. During the startup phase of WEST, plasma currents of the order of a few kilo amperes were measured despite much larger current of the order of hundreds of kilo amperes flowing in nearby conducting structures. The diagnostic is now fully operational and exhibits a noise level of about 0.5 mT on the magnetic field, and 2.0 mWb on flux loops allowing identifying the plasma boundary with an accuracy of a few millimeters on a 2 ms time cycle.

Resistive reduced MHD modeling of multi-edge-localized-mode cycles in Tokamak X-point plasmas.

The full dynamics of a multi-edge-localized-mode (ELM) cycle is modeled for the first time in realistic tokamak X-point geometry with the nonlinear reduced MHD code jorek. The diamagnetic rotation is found to be instrumental to stabilize the plasma after an ELM crash and to model the cyclic reconstruction and collapse of the plasma pressure profile. ELM relaxations are cyclically initiated each time the pedestal gradient crosses a triggering threshold. Diamagnetic drifts are also found to yield a near-symmetric ELM power deposition on the inner and outer divertor target plates, consistent with experimental measurements.

Mechanism of edge localized mode mitigation by resonant magnetic perturbations.

A possible mechanism of edge localized modes (ELMs) mitigation by resonant magnetic perturbations (RMPs) is proposed based on the results of nonlinear resistive magnetohydrodynamic modeling using the jorek code, realistic JET-like plasma parameters and an RMP spectrum of JET error-field correction coils (EFCC) with a main toroidal number n=2 were used in the simulations. Without RMPs, a large ELM relaxation is obtained mainly due to the most unstable medium-n ballooning mode. The externally imposed RMP drives nonlinearly the modes coupled to n=2 RMP which produce small multimode relaxations, mitigated ELMs. The modes driven by RMPs exhibit a tearinglike structure and produce additional islands. Mitigated ELMs deposit energy into the divertor mainly in the structures ("footprints") created by n=2 RMPs, however, slightly modulated by other nonlinearly driven even harmonics. The divertor power flux during a ELM phase mitigated by RMPs is reduced almost by a factor of 10. The mechanism of ELM mitigation by RMPs proposed here reproduces generic features of high collisionality RMP experiments, where large ELMs are replaced by small, much more frequent ELMs or magnetic turbulence. Total ELM suppression was also demonstrated in modeling at higher RMP amplitude.

Observation of lobes near the X point in resonant magnetic perturbation experiments on MAST.

The application of nonaxisymmetric resonant magnetic perturbations (RMPs) with a toroidal mode number n = 6 in the MAST tokamak produces a significant reduction in plasma energy loss associated with type-I edge localized modes (ELMs), the first such observation with n > 3. During the ELM mitigated stage clear lobe structures are observed in visible-light imaging of the X-point region. These lobes or manifold structures, that were predicted previously, have been observed for the first time in a range of discharges and their appearance is correlated with the effect of RMPs on the plasma; i.e., they only appear above a threshold when a density pump out is observed or when the ELM frequency is increased. They appear to be correlated with the RMPs penetrating the plasma and may be important in explaining why the ELM frequency increases. The number and location of the structures observed can be well described using vacuum modeling. Differences in radial extent and poloidal width from vacuum modeling are likely to be due to a combination of transport effects and plasma screening.

Active control of type-I edge-localized modes with n=1 perturbation fields in the JET tokamak.

Type-I edge-localized modes (ELMs) have been mitigated at the JET tokamak using a static external n=1 perturbation field generated by four error field correction coils located far from the plasma. During the application of the n=1 field the ELM frequency increased by a factor of 4 and the amplitude of the D(alpha) signal decreased. The energy loss per ELM normalized to the total stored energy, DeltaW/W, dropped to values below 2%. Transport analyses shows no or only a moderate (up to 20%) degradation of energy confinement time during the ELM mitigation phase.

Insulin-like growth factor system gene expression in women with type 2 diabetes and breast cancer.

BACKGROUND/AIMS: A twofold increased risk for breast cancer has been reported recently for women with late onset diabetes. Most studies showed that there were differences in serum concentrations of insulin-like growth factors and related proteins between women with and without diabetes who have breast cancer. This study investigated the expression of these markers at the cellular level in a cohort of women with and without type 2 diabetes who underwent biopsy because of a breast lump. METHODS: Relative quantitative analysis of specific mRNA sequences was performed after extraction and reverse transcription polymerase chain reaction amplification from formalin fixed and paraffin wax embedded tissues. Sixty seven breast surgical specimens from women with and without diabetes who did not have cancer and from women with and without diabetes who did have cancer were studied for insulin-like growth factor I (IGF-I), the IGF-I receptor (IGF-IR), insulin-like growth factor binding protein 3 (IGFBP-3), and oestrogen receptor 1 gene expression. RESULTS: The expression of IGF-I and IGF-IR was significantly lower in the cancer groups, whereas there was no significant difference for IGFBP-3 between women with and without cancer. Moreover, there was a good correlation between the expression of IGF-I and IGF-IR in women without cancer: this link was still present in breast tissue from patients with diabetes and cancer, whereas it was lost in patients without diabetes but with cancer. CONCLUSIONS: These differences in IGF-I/IGF-IR expression could contribute to the increased risk for breast cancer in women with type 2 diabetes.

Endothelial cell E- and P-selectin and vascular cell adhesion molecule-1 function as signaling receptors.

Previous studies have shown that polymorphonuclear leukocyte (PMN) adherence to endothelial cells (EC) induces transient increases in EC cytosolic free calcium concentration ([Ca2+]i) that are required for PMN transit across the EC barrier (Huang, A.J., J.E. Manning, T. M. Bandak, M.C. Ratau, K.R. Hanser, and S.C. Silverstein. 1993. J. Cell Biol. 120:1371-1380). To determine whether stimulation of [Ca2+]i changes in EC by leukocytes was induced by the same molecules that mediate leukocyte adherence to EC, [Ca2+]i was measured in Fura2-loaded human EC monolayers. Expression of adhesion molecules by EC was induced by a pretreatment of the cells with histamine or with Escherichia coli lipopolysaccharide (LPS), and [Ca2+]i was measured in single EC after the addition of mAbs directed against the EC adhesion proteins P-selectin, E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), or platelet/endothelial cell adhesion molecule-1 (PECAM-1). Both anti-P- and anti-E-selectin mAb, as well as anti-VCAM-1 mAb, induced transient increases in EC [Ca2+]i that were comparable to those induced by 200 microM histamine. In contrast, no effect was obtained by mAbs directed against the endothelial ICAM-1 or PECAM-1. PMN adherence directly stimulated increases in [Ca2+]i in histamine- or LPS-treated EC. mAbs directed against leukocyte CD18 or PECAM-1, the leukocyte counter-receptors for endothelial ICAM-1 and PECAM-1, respectively, did not inhibit PMN-induced EC activation. In contrast, mAb directed against sialyl Lewis x (sLex), a PMN ligand for endothelial P- and E-selectin, completely inhibited EC stimulation by adherent PMN. Changes in EC [Ca2+]i were also observed after adherence of peripheral blood monocytes to EC treated with LPS for 5 or 24 h. In these experiments, the combined addition of mAbs to sLex and VLA-4, the leukocyte counter-receptor for endothelial VCAM-1, inhibited [Ca2+]i changes in the 5 h-treated EC, whereas the anti-VLA-4 mAb alone was sufficient to inhibit [Ca2+]i changes in the 24 h-treated EC. Again, no inhibitory effect was observed with an anti-CD18 or anti-PECAM-1 mAb. Of note, the conditions that induced changes in EC [Ca2+]i, i.e. , mAbs directed against endothelial selectins or VCAM-1, and PMN or monocyte adhesion to EC via selectins or VCAM-1, but not via ICAM-1 or PECAM-1, also induced a rearrangement of EC cytoskeletal microfilaments from a circumferential ring to stress fibers. We conclude that, in addition to their role as adhesion receptors, endothelial selectins and VCAM-1 mediate endothelial stimulation by adhering leukocytes.

Prevalence and biological effects of anti-trophoblast and anti-endothelial cell antibodies in patients with recurrent spontaneous abortions.

PROBLEM: Trophoblasts and endothelial cells represent a potential target for antibodies in women with recurrent spontaneous abortions. These antibodies have been shown to be associated with anti-phospholipid antibodies. Are they also present in women with unexplained pregnancy losses in the absence of anti-phospholipid antibodies? METHOD OF STUDY: The anti-trophoblast antibodies were tested by an immunofluorescence assay on cells purified from pooled first-trimester placentae, whereas the anti-endothelial cell antibodies were measured by enzyme-linked immunoadsorbent assay (ELISA) on cells isolated from the umbilical vein and were cultured to confluence. The cytotoxicity of trophoblasts was evaluated in a homologous system. The expression of adhesion molecules on endothelial cells was quantitated by ELISA using specific monoclonal antibodies, and the expression of tissue factor was quantitated by a chromogenic assay measuring the formation of factor Xa. RESULTS AND CONCLUSIONS: Complement-fixing antibodies to trophoblast represent a better marker to discriminate patients with recurrent spontaneous abortions from controls and are cytotoxic for the target cells. Anti-endothelial antibodies are also present in these patients and exhibit pro-inflammatory and pro-coagulant activities.

The cytolytically inactive terminal complement complex activates endothelial cells to express adhesion molecules and tissue factor procoagulant activity.

The membrane attack complex of complement (C) in sublytic concentrations stimulates endothelial cells (EC) to express adhesion molecules and to release biologically active products. We have examined the ability of a cytolytically inactive form of this complex, which is incapable of inserting into the cell membrane, to upregulate the expression of adhesion molecules and of tissue factor (TF) procoagulant activity. The inactive terminal C complex (iTCC) was prepared by mixing C5b6, C7, C8, and C9 and was purified by fast protein liquid chromatography on a Superose 12 column. Binding of this complex to EC was found to be dose dependent and was inhibited by anti-C9 antibodies, as assessed both by ELISA using an mAb anti-C9 neoantigen and by measuring cell-bound 125I-labeled iTCC. Exposure of EC to iTCC resulted in a dose- and time-dependent expression of endothelial leukocyte adhesion molecule 1, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 accompanied by increased levels of the corresponding mRNA, but not in the rapid expression of P-selectin. Inactive TCC also induced increased TF activity evaluated by a chromogenic assay that measures the formation of factor Xa. These effects were inhibited by anti-C9 antibodies. The data support the conclusion that iTCC may induce proinflammatory and procoagulant activities on EC.

Low density lipoprotein-apheresis decreases oxidized low density lipoproteins and monocyte adhesion to endothelial cells.

The mutual interaction between monocytes and low density lipoprotein (LDL) in atherogenesis prompted a test of the hypothesis that LDL-apheresis could reduce the adhesive properties of monocytes to endothelium; and therefore interfere with a key mechanism in atheroma formation. Five patients affected by heterozygous familial hypercholesterolemia were studied. All patients received LDL-apheresis treatment with selective adsorption of LDL-cholesterol on dextran-sulphate columns. Low density lipoprotein particles were isolated by sequential preparative ultracentrifugation and subfractionated by ion exchange high performance liquid chromatography. Thiobarbituric acid reacting products of lipid peroxidation were measured fluorometrically. Vitamin E was estimated by high performance liquid chromatographic technique. Monocytes were isolated from patients blood before and 1 day after LDL-apheresis by Percoll gradient. The blood samples for monocyte adhesion were drawn from control subjects for 2 consecutive days. The adhesion of monocytes to an endothelial monolayer was evaluated by assaying the peroxidase content of the adherent monocytes. Low density lipoprotein-apheresis reduced total cholesterol (-65%; p < 0.01), LDL-cholesterol (-75%; p < 0.01), triglycerides (-51%; p < 0.05), and fibrinogen (-28%; p < 0.01). With LDL-apheresis treatment, a reduction of 54% in oxidized LDLs was observed; vitamin E concentration significantly increased in LDLs (+ 14.2%; p < 0.05). The monocyte adhesion decreased by approximately 61% after apheresis; the variation became statistically significant (-65%; p < 0.01) when endothelial cells were stimulated by lipopolysaccaride.

Leptospira icterohemorrhagiae and leptospire peptidolgycans induce endothelial cell adhesiveness for polymorphonuclear leukocytes.

We have examined the effect of the virulent Leptospira interrogans strain Teramo, serotype icterohemorrhagiae, on the adherence of human neutrophilic polymorphonuclear leukocytes (PMN) to cultured human umbilical vein endothelial cells (HEC). Selective pretreatment of HEC with intact or sonicated leptospires caused a dose- and time-dependent increase of HEC-PMN adhesion (13.2% +/- 2.5% adherence to untreated HEC versus 46.3% +/- 5.6% adherence to HEC pretreated for 4 h with 10(8) intact leptospires per ml [mean +/- standard error of six experiments; P < 0.001]). In contrast, selective leptospire pretreatment of PMN or the addition of leptospires during the adherence assay did not alter HEC-PMN adherence. Leptospire induction of endothelial-cell adhesiveness occurred without detectable HEC damage and was prevented by RNA and protein synthesis inhibitors and by monoclonal antibodies to the CD11/CD18 adhesion complex of neutrophils and to the endothelial-leukocyte adhesion molecule 1 (ELAM-1) of endothelial cells. Similar results were obtained with pretreatment of HEC with interleukin-1 or with the lipopolysaccharide (LPS) of the gram-negative bacterium Escherichia coli. The possibility that contamination by the LPS of gram-negative bacteria could be involved in the induction of HEC adhesiveness was ruled out by the observation that the LPS inhibitor polymyxin B, which abolished the proadhesive effect of E. coli LPS, was ineffective in inhibiting leptospire- as well as interleukin-1-induced adherence. Similarly, leptospire LPSs seemed to have no role in the increase of endothelial-cell adhesiveness, since pretreatment of HEC with a leptospire LPS extract (phenol-water method) or with a leptospire total lipid extract failed to induce the proadhesive phenotype for neutrophils. Instead, peptidoglycans extracted from our leptospires actively stimulated the endothelial proadhesive activity for neutrophils (16.5% +/- 2.1% adherence to untreated HEC versus 51.2% +/- 2.9% adherence to HEC pretreated for 4 h with 1 microgram of peptidoglycan per ml; [mean +/- standard error of four experiments; P < 0.001]). This peptidoglycan-induced activity was inhibited by monoclonal antibodies to the CD11/CD18 adhesion complex and to ELAM-1 but not by polymyxin B. We conclude that peptidoglycans from pathogenic leptospires are among the molecules that can directly activate vascular endothelial cells to increase their adhesiveness for neutrophilic granulocytes. These observations may contribute to a better understanding of the mechanisms whereby non-gram-negative bacteria modulate the local and systemic inflammatory reaction.

Effects of endotoxin in mice bearing solid metastasizing tumors and treated with lysozyme hydrochloride.

The effects of the i.v. administration of endotoxin (6.25-50 micrograms/mouse on day 13 after tumor implantation) in mice treated orally with lysozyme hydrochloride (100 mg/kg on days 5-12 from tumor implantation) were examined using Lewis lung carcinoma in the C57Bl mouse and MCa mammary carcinoma of CBA mice. On primary tumor growth, endotoxin alone causes a dose-dependent and statistically significant reduction with a nadir on day +2 from endotoxin treatment. Combined with lysozyme, endotoxin causes an effect independent of the dose used, corresponding to the effect caused by endotoxin alone at the dose of 25 micrograms/mouse. No tumor regression was recorded in any of the treated groups. Endotoxin is virtually devoid of effects at the metastatic level. In the same conditions, lysozyme causes a reduction of primary tumor growth and a more pronounced inhibition of lung metastasis formation as expected from its already reported effects. The antitumor activity of endotoxin, unlike lysozyme, can be ascribed to tumor hemorrhagic necrosis due to tumor necrosis factor (TNF) production, as determined in tumor homogenates. Endotoxin does not increase the antitumor effects in mice treated with lysozyme, as expected from the data obtained with the more immunogenic SA1 sarcoma, although lysozyme increased the mitogenic response to ConA of ex vivo isolated splenocytes, in vitro cultured in the presence of IL-2.

Mechanisms of eosinophil adherence to cultured vascular endothelial cells. Eosinophils bind to the cytokine-induced ligand vascular cell adhesion molecule-1 via the very late activation antigen-4 integrin receptor.

We have examined the mechanisms involved in the adherence of normal peripheral blood eosinophils to cultured human umbilical vein endothelial cells (HEC) under three conditions: (a) adherence in the absence of treatment of HEC or eosinophils with activating agents (basal adherence); (b) adherence induced by stimulation of eosinophils with phorbol ester (eosinophil-dependent adherence); and (c) adherence induced by pretreatment of HEC with LPS, tumor necrosis factor (TNF), or IL-1 (endothelial-dependent adherence). A mechanism was identified that was equally active in basal, eosinophil-dependent, and endothelial-dependent adherence. This mechanism was optimally active in the presence of both Ca++ and Mg++, and reduced in the presence of Ca++ only or Mg++ only. Furthermore, like the other mechanisms of eosinophil adherence, it was active at 37 degrees C but not at 4 degrees C. A second mechanism of adherence was involved in eosinophil- and in endothelial-dependent adherence. This mechanism was dependent on the CD11/CD18 adhesion complex of eosinophils (i.e., inhibited by anti-CD18 MAb) and it was active in the presence of Ca++ and Mg++ or Mg++ only, but not Ca++ only. The third mechanism of adherence was specific for endothelial-dependent adherence. It involved the endothelial ligand vascular cell adhesion molecule-1 (VCAM-1) and the eosinophil receptor very late activation antigen-4 (VLA-4, CD49d/CD29, i.e., inhibited by anti-VCAM-1 MAb or anti-VLA-4 MAb). This mechanism was active in the presence of Ca++ and Mg++ but not of Ca++ only or Mg++ only, and was not up- or downregulated when eosinophils were stimulated with phorbol ester. In contrast, the endothelial leukocyte adhesion molecule-1 (ELAM-1), that binds neutrophils and monocytes, was not involved in eosinophil adherence to LPS-, TNF-, or IL-1-stimulated HEC (i.e., not inhibited by anti-ELAM-1 MAb). We conclude that eosinophils, like monocytes and lymphocytes, bind to the cytokine-induced endothelial ligand VCAM-1 via the integrin receptor VLA-4.

Identification and partial characterization of a cytolytic toxin produced by Gardnerella vaginalis.

Generation and release into the culture medium of a cytolytic toxin by Gardnerella vaginalis has been demonstrated. Addition of starch and of the nonionic detergent Tween 80 to the culture medium was essential to recover cytolytic activity. A protein with an apparent molecular mass of 61 to 63 kDa was purified from the culture supernatants showing lytic activity towards erythrocytes and nucleated cells, such as human endothelial cells and human neutrophils. The protein had marked selectivity for human erythrocytes, while erythrocytes from other species were not lysed or were lysed at much higher concentrations of the protein than those needed for human erythrocytes. The cytolytic activity was remarkably unstable in polar media, but was stabilized by nonionic detergents, by binding, or by insertion into the target cell membrane, suggesting its amphiphilic nature.

Mutual influence between eosinophil peroxidase (EPO) and neutrophils: neutrophils reversibly inhibit EPO enzymatic activity and EPO increases neutrophil adhesiveness.

The effects of the interactions between eosinophil peroxidase (EPO) and neutrophils were studied. It is shown that binding of EPO to neutrophils results on the one hand in reversible inhibition of EPO peroxidase activity and, on the other, in an increased neutrophil aggregation and neutrophil adhesion to endothelial cell monolayers. After prolonged periods of exposure to EPO, neutrophils also show a decreased ability to exclude the vital dye erythrosin B. The reversible inhibition of EPO activity may represent a means of keeping under control the oxidative potential of EPO, while the increased neutrophil aggregation and adherence to endothelial cells suggest that EPO may influence at least two key events of inflammation, that is, the margination of neutrophils and/or their accumulation in the inflammatory site.

Uptake of human eosinophil peroxidase and myeloperoxidase by cells involved in the inflammatory process.

We have recently shown that human neutrophils bind and internalize human eosinophil peroxidase (EPO) but not myeloperoxidase (MPO). In the present work, we studied the interactions of human EPO and MPO with other cells that may be involved in the inflammatory process, i.e., lymphocytes, monocytes, platelets, fibroblasts, and endothelial cells. The results indicate that EPO is bound by all the cell types considered, but is efficiently internalized only by lymphocytes, monocytes, and endothelial cells. Conversely, MPO binds appreciably only to fibroblasts and endothelial cells, although with a lower affinity than EPO, but its internalization by any of the cell types studied is hardly detectable. Furthermore, both peroxidases bind strongly to collagen fibers, whereas only EPO binds to elastin. The results suggest that EPO, owing to its high cytophilia, exerts its biological activity close to the site at which it is released from the eosinophil.