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Abstract: The parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross-section was measured for elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required to measure the few-part-per-million asymmetry, the experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics, processing only a small fraction of the events, was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events from the 128 detector pairs at a mean rate of 2MHz per detector pair with low deadtime and with minimal helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to forward-angle measurements. [Copyright &y& Elsevier]

QED radiative corrections have been calculated for leptonic and hadronic variables in parity-violating elastic ep scattering. For the first time, the calculation of the asymmetry in the elastic radiative tail is performed without the peaking-approximation assumption in hadronic variables configuration. This method has been validated in a comparison with the PVA4 data. It has been also used to evaluate the radiative corrections to the parity-violating asymmetry measured in the G0 experiment. The results obtained are here presented. [ABSTRACT FROM AUTHOR]

Since 1987 the antiphospholipid syndrome has been recognized as a major cause of acquired thrombophilia, whether it is associated with systemic lupus erythematosus or occurs as a free-standing syndrome (primary form). This autoimmune condition associates in young patients recurrent thrombosis (both venous and/or arterial) and/or a variety of obstetric complications with the persistent presence of antiphospholipid antibodies (aPL). These traditionally comprise anticardiolipin antibodies and lupus anticoagulants, respectively detected by immunological and clotting tests. Despite their name aPL do not bind to phospholipids per se, but are directed at phospholipid-binding plasma proteins, especially β2-glycoprotein I and prothrombin. Because the risk of recurrence is high, the standard of care is prolonged and high-intensity warfarin (INR near 3) after a venous thromboembolic event, together with the management of associated vascular risk factors. Prevention of adverse obstetric outcomes is frequently achieved by a combination of low-dose aspirin and heparin. [Copyright &y& Elsevier]

The M RC OX-45 and OX-46 mouse monoclonal antibodies recognize a rat cell surface glycoprotein of 45,000 MW that is present on a wide variety of haematopoietic cells and on endothelial cells. MRC OX-45 IgG or F(ab')2 blocked the primary mixed lympocyte response (MLR) and the secondary response of T lymphocytes to the soluble antigen DNP-BGG. In contrast, the antibodies had no effect on the cytotoxic activity of specific (CTL) or non-specific (NK) killer cells or on proliferative responses stimulated by lectins or oxidative mitogenesis. The inhibitory effect was at the level of stimulator cells rather than responders since mouse anti-rat xenogeneic MLRs were inhibited but rat anti-mouse responses were unaffected. However, the effect was not a direct one because inhibition was seen when irradiated spleen cells were used as stimulators but not when cell populations highly enriched for dendritic cells were used. In the latter case, inhibition potentiated by antibody could be resto red if a peritoneal cell population enriched for macrophages was added back to the cultures. The inhibitory effects of these monoclonal antibodies seem most likely to be due to potentiation of non- specific suppression by macrophages. [ABSTRACT FROM AUTHOR]

The IgG subclass and light chain distribution of antiphospholipid antibodies (aPL) occurring in autoimmune patients were determined by means of two radioimmunoassays using either cardiolipinor β2 glycoprotein 1 (β2GP1)-coated microtitre plates and mouse MoAbs. Of 50 sera selected for positivity of anticardiolipin antibodies (ACA) of the IgG isotype, 32 (64%) possessed anti-β2GPI antibodies and their presence was closely associated with clinical features of the antiphospholipid syndrome. Good correlations were found between ACA and anti-β 2GP1 antibodies when considering antibody level and patterns of light chain and IgG subclass, suggesting that, overall, the same antibodies were being measured. Light chain analysis showed the polyclonal origin of these antibodies and. in most sera, a trend towards use of λ chain. Among sera positive for anti-β 2GP1 antibodies, IgG2 was the major subclass reactive with &beta2GP1 and cardiolipin (87% and 74% of the IgG antibody activity, respectively). In contrast, in the group of 18 sera lacking anti-β 2GPI antibodies, ACA were largely restricted to IgG3, with a lesser contribution by IgG1. A few selected sera from the anti-β 2GP1-positive group were shown to contain mixtures of antibodies that required β 2GP1 (restricted to IgG2 present in large amounts) and did not require this cofactor (restricted to IgG3 and/or IgG1 present in low amounts) for their reactivity with cardiolipin. There was no contribution of glycosylation to the epitopes recognized by anti-βGP1 antibodies, even though human anti-carbohydrate antibodies are restricted to the IgG2 subclass. These findings further emphasize the intra- and interindividual heterogeneity of aPL, and should help to discriminate clinically relevant specificies. [ABSTRACT FROM AUTHOR]

We studied 51 sera from patients with systemic lupus erythematosus to determine the relationship of their anti-phospholipid activity to their anti-erythrocyte and complement activation properties. Forty-nine per cent of the sera had anti-phospholipid activity as demonstrated by ELISA using a panel of anionic phospholopids, and most of these also bound to neutral phospholipids, albeit to a lesser extent. A cellular radioimmunoassay was used for the detection of immunoglobulin and C3 binding to normal erythrocytes (intact, enzyme-treated or glutaraldehyde-fixed) following incubation with patient sera. The levels of IgG anti-phospholopid correlated with hypocomplementaemoa and with immunoglobulin binding (paralleled by a deposition of c3 fragments) to the three types of erythrocytes, although most strongly to fixed cells. Immunoglobulin binding to intact erythrocytes correlated primarily with reactivity against neutral phospholipids. The specificity for phospholipid epitopes of immunoglobulin adsorbed onto erythrocytes was confirmed by acid elution followed by testing in ELISA. These data suggest that some anti-phospholipid antibody subsets may bind to erythrocytes in vivo, thus accounting for the observed association of these antibodies with positive direct antiglobulin tests. [ABSTRACT FROM AUTHOR]

A monoclonal IgM κ from a patient with Waldenström's macroglobulinaemia(IgM-Rod) was found to react at temperatures below 28 C with all tissue basement membranes and the cell coat of nonhaematopoietic cells. IgM-Rod antibody was directed against heparan sulphate side chains of heparan sulphate proteoglycans as shown by binding in a solid-phase ELISA to heparan sulphate glycosaminoglycans but not to other purified subcomponents of the extracellular matrix: and by specific inhibition of the observed reactivity by heparitinase treatment. IgM-Rod showed crossreactivity by indirect immunofluorescence with an as yet unidentified structure expressed in the nucleus during cell division and becoming associated with the mitotic spindle apparatus. The coexistence of both binding activities for heparan sulphate and nuclei determinants in the same IgM molecule was deduced from adsorption-elution experiments and from the inhibitory effect of a mouse monoclonal anti-idiotypie antibody directed against the paratope of IgM-Rod. [ABSTRACT FROM AUTHOR]

The effect of complement fragments C3b and C4b, on the triggering of antigen-specific human T-cell clones by Epstein-Barr virus-transformed human lymphoblastoid 13 cells (LCL) when these fragments are covalently coupled to the antigen tetanus toxin (TT) is described. TT was chemically cross-linked to purified C3b [(TT-C3b)n], C4b [(TT-C4b)n] or bovine serum albumin [(TT-BSA)n] as a control. T-cell activation was quantified by tritiated thymidine incorporation and 51Cr release. (TT- C3b)n and ( TT-C4b)n induced proliferative responses comparable to (TT-BSA)n but at 18-25 and 4- 6 lower concentrations, respectively. This enhancing effect required the covalent cross-linking of the complement fragments to the antigen and involved intracellular processing of the latter by LCL. Antigen presentation was similarly enhanced when measuring the cytotoxic activity of a helper T-cell clone against LCL previously pulsed with (TT-C3b)n or (TT-C4b)n compared with (TT-BSA)n. Binding studies, carried out on LCL using TT radiolabelled with 125I before cross-linking, indicated that (TT-C3b)n and (TT-C4b)n gave three- to four-fold more binding than (TT-BSA)n. Addition of antibodies against CR! and CR2 or proteolytic removal of these complement receptors with trypsin inhibited by about 60% the enhancing effect of TT-bound C3b and C4b in both binding and functional assays. These results indicate that binding of C3b or C4b to antigen enhances antigen- specific proliferative and cytotoxic responses of T cells by targeting opsonized antigen onto complement receptors CR 1 and CR2 of LCL. The putative significance of these findings in terms of regulation of immune responses by complement is discussed. [ABSTRACT FROM AUTHOR]

Abstract: In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part-per-million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cherenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed. [Copyright &y& Elsevier]

Abstract: We report seven cases of arterial gas embolism originating from the lung that occurred in anaesthesia and intensive care unit in the very hospital where our regional hyperbaric oxygen facility is. They complicated lung surgery or trauma and/or followed a support by positive-pressure ventilation. Diagnosis was most often delayed, because of some scepticism of the physicians confronted with a variety of clinical features. The prognosis was bad with four deaths, despite treatment with hyperbaric oxygen in three cases. [Copyright &y& Elsevier]

Abstract: A hyperon–nucleon scattering experiment, KEK-PS E289, was carried out at the K2 beam line in KEK. We adopted a scintillating fiber active target as a hydrogen target for hyperon production and subsequent hyperon–nucleon scattering. We collected more data than in a previous experiment, KEK-PS E251. In this paper, the differential cross sections for elastic scattering in the incident momentum range from 350 to 750 MeV/c are presented and compared with theoretical predictions from the Nijmegen group (Nijmegen Soft Core 97) and the Kyoto–Niigata group (RGM-FSS and fss2). [Copyright &y& Elsevier]

It is of considerable interest to ascertain whether a hollow fiber cartridge containing histidine immobilized on polyethylenevinyl alcohol membrane (His-PEVA) is able to retain specific autoantibodies involved in antiphospholipid syndrome. To this end diluted patient pathogenic plasma containing high levels of anti-β2-glycoprotein I (anti-β2GPI) and antiprothrombin antibodies was processed through the functionalized cartridge. The adsorbed material was then eluted under mild conditions and analyzed; an enrichment of the eluted fractions in total IgG and more specifically in IgG2 subclass was observed, compared with the injected sample. Enzyme-linked immunosorbent assay tests showed a higher specific binding of antiprothrombin and anti-β2GPI in these fractions. This was in accordance with the concomitant higher anticoagulant activity measured on the same fractions. All in vitro results clearly demonstrated the ability of the His-PEVA cartridge to preferentially adsorb these autoantibodies. Hence the functionalized cartridge represents a potential tool for the treatment of antiphospholipid syndrome by selective extracorporeal removal of IgG. [ABSTRACT FROM AUTHOR]

Focuses on an active target with plastic scintillating fibers for hyperon-proton scattering. Information on scintillating fiber block target; Uses of image intensifier tubes; Results of the image data analysis.

Background: This study aims to determine the potential risk factors associated with the development of severe diving-related spinal cord decompression sickness (DCS). Methods: Two hundred and seventy nine injured recreational divers (42 ± 12 years; 53 women) presenting symptoms of spinal cord DCS were retrospectively included from seven hyperbaric centers in France and Belgium. Diving information, symptom latency after surfacing, time interval between symptom onset and hyperbaric treatment were studied. The initial severity of spinal cord DCS was rated with the Boussuges severity score, and the presence of sequelae was evaluated at 1 month. Initial recompression treatment at 2.8 ATA with 100% oxygen breathing or deeper recompression up to 4 or 6 ATA with nitrogen or helium-oxygen breathing mixture were also recorded. Results: Twenty six percent of DCS had incomplete resolution after 1 month. Multivariate analysis revealed several independent factors associated with a bad recovery: age ≥42 [OR 1.04 (1-1.07)], depth ≥39 m [OR 1.04 (1-1.07)], bladder dysfunction [OR 3.8 (1.3-11.15)], persistence or worsening of clinical symptoms before recompression [OR 2.07 (1.23-3.48)], and a Boussuges severity score >7 [OR 1.16 (1.03-1.31)]. However, the time to recompression and the choice of initial hyperbaric procedure did not significantly influence recovery after statistical adjustment. Conclusions: Clinical symptoms of spinal cord DCS and their initial course before admission to the hyperbaric center should be considered as major prognostic factors in recovery. A new severity score is proposed to optimize the initial clinical evaluation for spinal cord DCS. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Pulmonary oedema in self-contained underwater breathing apparatus diving is an accident whose risk factors, conditions of occurrence and incidence are not well-known. The aim of this study was to evaluate the frequency, the risk factors and the evolution of this accident. Study design: Retrospective case study and prospective frequency study. Patients and methods: Study covering the Brittany region and performed in two steps with distinct objectives: a review of cases diagnosed between 2002 and 2007, and a one-year study of cases reported by emergency physicians. Diagnosis was based on the history, a respiratory distress, auscultation and radiologic features. Results: Nineteen cases were reported, of which one was recurrent. The mean age of patients was 49 years. Divers without heart disease were involved, as well as divers with hypertension (eight cases) or valve abnormalities (three cases). Stress and/or physical exertion were involved. Dyspnoea, cough and haemoptysis were the most common symptoms; in addition, two cases of cardiac arrest and three of loss of consciousness were observed. Chest radiography was unsensitive (normal in four cases), contrasting with abnormal thoracic CT scan in all cases. Symptoms resolved rapidly with oxygen, except for two divers who died. We identified five cases over one year, one of which lethal. Conclusion: This accident is not a rare event and may have serious consequences. Oldest divers submitted to stress and/or effort are at higher risk. [Copyright &y& Elsevier]

Purpose. – The association of antiphosphatidylethanolamine antibodies (aPE) as the only antiphospholipid antibody with antiphospholipid syndrome (APS) is discussed. The aPE was described as the sole antibody in many cases suggesting APS. aPE was not included in the Sapporo criteria for the classification of APS.Methods. – We investigated the clinical features of 20 patients with aPE only; 17 patients had symptoms potentially related to APS (group 1) and three had other manifestations (group 2).Results. – There were 15 women and five men, mean age was 35 ± 12 years at the beginning. In group 1 (n = 17), ten patients presented arterial thrombosis, nine venous thrombosis (five had both), and six microvascular thrombosis (livedo reticularis, lacunar pathology). The aPE postivity was persistent in 13 patients. A subgroup of four patients (three women) presented arteriosclerosis with peripheral arteriopathy which started before 45 years of age. They had another atherosclerosis risk factor associated with aPE persistence. In group 2 (n = 3), there was no thrombotic event, one demyelinating pathology, one microvascular pathology, and one arterial dysplasia. The aPE positivity was never confirmed. Finally, 13 patients presented an APS with aPE only, confirmed at least 8 weeks later.Conclusions. – Our study points out that testing for aPE would be of interest for patients when symptoms were potentially related to APS, particularly when other antiphospholipid antibodies were negative. This description questions the enlargement of the APS biological criteria defined in Sapporo. The role of aPE in atherosclerosis is considered. [ABSTRACT FROM AUTHOR]

Objective: To determine in patients with systemic lupus erythematosus (SLE) or with primary antiphospholipid syndrome (PAPS) the prevalence of cerebral magnetic resonance imaging changes (MRI) and the relationship with antiphospholipid antibodies. Methods: Twenty-nine consecutive SLE patients, 24 PAPS patients and 31 healthy controls were prospectively included in the study and underwent MRI Scan over a 1-year period. MRI scans were analyzed separately by a neuroradiologist for white matter changes [periventricular hyperintensity (PVH) (0–6 scale), deep white matter hyperintensity (WMH) (0–24 scale)], and one neurologist for cerebral atrophy (0–39 scale) and stroke subtypes. Statistical assessment consisted of a discriminant analysis performed with SAS-package with MRI data as dependent variables and, as independent variables, age, sex, arterial hypertension, diabetes mellitus, cardiopathy, migraine, neurological symptoms, antiphospholipid antibodies, SLE, steroid treatment. Results: The prevalence of cerebral atrophy was increased in both SLE and PAPS groups relative to controls. PVH and WMH scores were significantly higher in SLE and PAPS than in controls. Focal infarct did not differ in the SLE group when compared with PAPS. PVH and WMH scores were significantly higher in patients with neurological symptoms. Using a correlation test we found a weak significant correlation between cerebral atrophy and lupus anticoagulant. The multivariate analysis found only three independent variables related to PVH and WMH: age, the diagnosis of SLE and cerebral atrophy. Conclusions: Age, presence of SLE and presence of neurological symptoms were independently related with WMH and PVH, but not antiphospholipid antibodies. [ABSTRACT FROM AUTHOR]