Inter-individual differences in HLA expression can impact the CDC crossmatch

How human leucocyte antigen (HLA) expression levels on human lymphocytes relate to clinically relevant in vitro cytotoxicity testing has not been defined. Here, cross-sectional (n = 14) and longitudinal (n = 6) semi-quantitative assessment of HLA expression on lymphocytes was performed. Complement-dependent cytotoxicity (CDC) and cellular allo-reactivity were assessed vis-à-vis target cells with defined levels of HLA expression. On CD4(+) and CD8(+) T-cells, and on B-cells, intra-individual HLA levels varied ≤1.5-fold, whereas inter-individual HLA expression varied 2.34-fold and 2.07-fold on CD4(+) and CD8(+) T-cells, respectively, and 2.90-fold on B-cells. Importantly, CDC crossmatch reactions induced by anti-HLA-A2 monoclonal antibody as well as patient sera solely containing HLA-A2 antibodies were significantly impacted by HLA-A2 expression levels on donor cells. Likewise, cytotoxicity of HLA-A2 reactive effector cells was induced proportionate to availability of HLA-A2. These data demonstrate that human HLA expression on lymphocytes from healthy blood donors is fairly stable intra-individually, yet varies significantly from person to person. Variability in HLA expression levels can impact functional cytotoxic reactions in vitro, including the widely used CDC crossmatch assay. Prospective studies are required to test the clinical relevance of this finding.

The Swiss National Registry for Primary Immunodeficiencies: report on the first 6 years' activity from 2008 to 2014

The Swiss National Registry for Primary Immunodeficiency Disorders (PID) was established in 2008, constituting a nationwide network of paediatric and adult departments involved in the care of patients with PID at university medical centres, affiliated teaching hospitals and medical institutions. The registry collects anonymized clinical and genetic information on PID patients and is set up within the framework of the European database for PID, run by the European Society of Immunodeficiency Diseases. To date, a total of 348 patients are registered in Switzerland, indicating an estimated minimal prevalence of 4·2 patients per 100 000 inhabitants. Distribution of different PID categories, age and gender are similar to the European cohort of currently 19 091 registered patients: 'predominantly antibody disorders' are the most common diseases observed (n = 217/348, 62%), followed by 'phagocytic disorders' (n = 31/348, 9%). As expected, 'predominantly antibody disorders' are more prevalent in adults than in children (78 versus 31%). Within this category, 'common variable immunodeficiency disorder' (CVID) is the most prevalent PID (n = 98/217, 45%), followed by 'other hypogammaglobulinaemias' (i.e. a group of non-classified hypogammaglobulinaemias) (n = 54/217, 25%). Among 'phagocytic disorders', 'chronic granulomatous disease' is the most prevalent PID (n = 27/31, 87%). The diagnostic delay between onset of symptoms and diagnosis is high, with a median of 6 years for CVID and more than 3 years for 'other hypogammaglobulinaemias'.

Creation and application of voxelised dosimetric models, and a comparison with the current methodology as used for the International Commission on Radiological Protection's Reference Animals and Plants

Over the past decade, the International Commission on Radiological Protection (ICRP) has developed a comprehensive approach to environmental protection that includes the use of Reference Animals and Plants (RAPs) to assess radiological impacts on the environment. For the purposes of calculating radiation dose, the RAPs are approximated as simple shapes that contain homogeneous distributions of radionuclides. As uncertainties in environmental dose effects are larger than uncertainties in radiation dose calculation, some have argued against more realistic dose calculation methodologies. However, due to the complexity of organism morphology, internal structure, and density, dose rates calculated via a homogenous model may be too simplistic. The purpose of this study is to examine the benefits of a voxelised phantom compared with simple shapes for organism modelling. Both methods typically use Monte Carlo methods to calculate absorbed dose, but voxelised modelling uses an exact three-dimensional replica of an organism with accurate tissue composition and radionuclide source distribution. It is a multi-stage procedure that couples imaging modalities and processing software with Monte Carlo N-Particle. These features increase dosimetric accuracy, and may reduce uncertainty in non-human biota dose-effect studies by providing mechanistic answers regarding where and how population-level dose effects arise.

The ultrasound compression sign to diagnose temporal giant cell arteritis shows an excellent interobserver agreement

OBJECTIVES

To compare the diagnostic performance between a vascular specialist and a rheumatologist not familiar with vascular ultrasound when applying the compression sign for the diagnosis of temporal arteritis.

METHODS

Sixty consecutive patients with suspicion of giant cell arteritis were examined by both examiners. Compression of the temporal artery on both sides (stem and both branches) was performed to define whether signs of vasculitis, no vasculitis or an indefinite result were present. Each examiner was blinded to the result of the other.

RESULTS

In 59/60 patients, the examiners found an identical result. The interobserver agreement (Krippendorf alpha) was 0.92.

CONCLUSIONS

The new compression sign for the diagnosis of temporal arteritis is a simple and robust sonographic marker with an excellent interobserver agreement.

Risk factors for pneumocystis pneumonia in giant cell arteritis: a single-centre cohort study

OBJECTIVES

Pneumocystis jiroveci pneumonia (PCP) is a life-threatening opportunistic infection. Few PCP cases in giant cell arteritis (GCA) have been described, but it remains unknown, which patients need PCP prophylaxis.

METHODS

Sixty-two patients with GCA from a prospective cohort were studied to identify treatment-related predictors of PCP infection.

RESULTS

Four PCP infections occurred, all in patients treated with methotrexate in addition to prednisone. Moreover, PCP is associated with higher cumulative PDN doses and severe lymphocytopenia (<400/μl).

CONCLUSIONS

Our findings support PCP-prophylaxis in GCA patients who are treated with methotrexate and PDN, and need high prednisone doses to achieve remission, or develop severe lymphocytopenia.

Composition of diet modifies colonization dynamics of Campylobacter jejuni in broiler chickens

AIMS

To evaluate the impact of diet composition on colonization dynamics of Camp. jejuni and on related physiological parameters in the chicken intestine.

METHODS AND RESULTS

A total of 54 1-day-old Ross 308 broiler chicks were randomly divided into three isocaloric and isonitrogenous dietary groups: maize-based (MB), wheat-based (WB) diet and wheat-based diet with NSP-degrading enzyme supplementation (WBES). Chickens were orally infected with 10(8)  CFU Camp. jejuni on day 14, and samples (n = 6) were collected on 7, 14 and 21 days postinfection (DPI), respectively. Colony forming units of Camp. jejuni of caecum and jejunum, short-chain fatty acid (SCFA) concentrations, pH values of the caecum, jejunal histomorphology and viscosity of jejunal chymus were measured. In case of WBES diet, lower Camp. jejuni colonization 14 DPI, higher jejunal viscosity, higher total SCFA concentrations in the caecum and enhanced jejunal histomorphology were observed compared to those measured in chickens fed MB diet.

CONCLUSIONS

The WBES diet altered Camp. jejuni colonization dynamics in the chicken intestine which resulted by higher SCFA concentrations in the caecum and by the change of gut morphology.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study proves that diet composition can modify Camp. jejuni colonization depending on sampling time point postinfection.

Thin film growth of Fe-based superconductors: from fundamental properties to functional devices. A comparative review

Fe-based superconductors bridge a gap between MgB2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today’s society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation.

Soft-X-ray ARPES facility at the ADRESS beamline of the SLS: concepts, technical realisation and scientific applications

Soft-X-ray angle-resolved photoelectron spectroscopy (ARPES) with photon energies around 1 keV combines the momentum space resolution with increasing probing depth. The concepts and technical realisation of the new soft-X-ray ARPES endstation at the ADRESS beamline of SLS are described. The experimental geometry of the endstation is characterized by grazing X-ray incidence on the sample to increase the photoyield and vertical orientation of the measurement plane. The vacuum chambers adopt a radial layout allowing most efficient sample transfer. High accuracy of the angular resolution is ensured by alignment strategies focused on precise matching of the X-ray beam and optical axis of the analyzer. The high photon flux of up to 10(13) photons s(-1) (0.01% bandwidth)(-1) delivered by the beamline combined with the optimized experimental geometry break through the dramatic loss of the valence band photoexcitation cross section at soft-X-ray energies. ARPES images with energy resolution up to a few tens of meV are typically acquired on the time scale of minutes. A few application examples illustrate the power of our advanced soft-X-ray ARPES instrumentation to explore the electronic structure of bulk crystals with resolution in three-dimensional momentum, access buried heterostructures and study elemental composition of the valence states using resonant excitation.

Design and properties of a cryogenic dip-stick scanning tunneling microscope with capacitive coarse approach control

We present the design, setup, and operation of a new dip-stick scanning tunneling microscope. Its special design allows measurements in the temperature range from 4.7 K up to room temperature, where cryogenic vacuum conditions are maintained during the measurement. The system fits into every (4)He vessel with a bore of 50 mm, e.g., a transport dewar or a magnet bath cryostat. The microscope is equipped with a cleaving mechanism for cleaving single crystals in the whole temperature range and under cryogenic vacuum conditions. For the tip approach, a capacitive automated coarse approach is implemented. We present test measurements on the charge density wave system 2H-NbSe2 and the superconductor LiFeAs which demonstrate scanning tunneling microscopy and spectroscopy data acquisition with high stability, high spatial resolution at variable temperatures and in high magnetic fields.

Evidence for a vortex-glass transition in superconducting Ba(Fe0.9Co0.1)2As2

Measurements of magneto-resistivity and magnetic susceptibility were performed on single crystals of superconducting Ba(Fe0.9Co0.1)2As2 close to the conditions of optimal doping. The high quality of the investigated samples allows us to reveal dynamic scaling behaviour associated with a vortex-glass phase transition in the limit of a weak degree of quenched disorder. Accordingly, the dissipative component of the ac susceptibility is reproduced well within the framework of Havriliak-Negami relaxation, assuming a critical power-law divergence for the characteristic correlation time τ of the vortex dynamics. Remarkably, the random disorder introduced by the Fe1-xCox chemical substitution is found to act on the vortices as a much weaker quenched disorder than previously reported for cuprate superconductors such as Y1-xPrxBa2Cu3O7-δ.

Low temperature ballistic spin transport in the S = 1/2 antiferromagnetic Heisenberg chain compound SrCuO2

We report zero and longitudinal magnetic field muon spin relaxation (μSR) measurements of the spin S = 1/2 antiferromagnetic Heisenberg chain material SrCuO2. We find that in a weak applied magnetic field B0 the spin-lattice relaxation rate λ follows a power law λ is proportional to B(0)(-n) with n = 0.9(3). This result is temperature independent for 5 K ≤ T ≤ 300 K. Within conformal field theory and using the Müller ansatz we conclude ballistic spin transport in SrCuO2.

Spin pseudogap in Ni-doped SrCuO2

The S=1/2 spin chain material SrCuO2 doped with 1% S=1 Ni impurities is studied by inelastic neutron scattering. At low temperatures, the spectrum shows a pseudogap Δ≈8  meV, absent in the parent compound, and not related to any structural phase transition. The pseudogap is shown to be a generic feature of quantum spin chains with dilute defects. A simple model based on this idea quantitatively accounts for the experimental data measured in the temperature range from 2 to 300 K, and allows us to represent the momentum-integrated dynamic structure factor in a universal scaling form.

Novel in situ cell for Raman diagnostics of lithium-ion batteries

A novel in situ cell for Raman diagnostics of working lithium-ion batteries is described. The design closely mimics that of standard battery testing cells and therefore allows to obtain Raman spectra under representative electrochemical conditions. Both cathode and anode materials can be studied. First results on the intercalation of a Li1-xCoO2 cathode material demonstrate the potential of the experimental approach for structural studies and underline the importance of studying lithium-ion batteries at work.