Molecular and Cellular Requirements for the Assembly of Tertiary Lymphoid Structures

At sites of chronic inflammation, recruited immune cells form structures that resemble secondary lymphoid organs (SLOs). Those are characterized by segregated areas of prevalent T- or B-cell aggregation, differentiation of high endothelial venules (HEVs) and local activation of resident stromal cells. B-cell proliferation and affinity maturation towards locally displayed autoantigens have been demonstrated at those sites, known as tertiary lymphoid structures (TLSs). TLS formation has been associated with local disease persistence and progression as well as increased systemic manifestations. While bearing a similar histological structure to SLO, the signals that regulate TLS and SLO formation can diverge, and a series of pro-inflammatory cytokines has been ascribed as responsible for TLS formation at different anatomical sites. Here we review the structural elements as well as the signals responsible for TLS aggregation, aiming to provide an overview to this complex immunological phenomenon.

Whole genome sequencing of Shigella sonnei through PulseNet Latin America and Caribbean: advancing global surveillance of foodborne illnesses

Objectives

Shigella sonnei is a globally important diarrhoeal pathogen tracked through the surveillance network PulseNet Latin America and Caribbean (PNLA&C), which participates in PulseNet International. PNLA&C laboratories use common molecular techniques to track pathogens causing foodborne illness. We aimed to demonstrate the possibility and advantages of transitioning to whole genome sequencing (WGS) for surveillance within existing networks across a continent where S. sonnei is endemic.

Methods

We applied WGS to representative archive isolates of S. sonnei (n = 323) from laboratories in nine PNLA&C countries to generate a regional phylogenomic reference for S. sonnei and put this in the global context. We used this reference to contextualise 16 S. sonnei from three Argentinian outbreaks, using locally generated sequence data. Assembled genome sequences were used to predict antimicrobial resistance (AMR) phenotypes and identify AMR determinants.

Results

S. sonnei isolates clustered in five Latin American sublineages in the global phylogeny, with many (46%, 149 of 323) belonging to previously undescribed sublineages. Predicted multidrug resistance was common (77%, 249 of 323), and clinically relevant differences in AMR were found among sublineages. The regional overview showed that Argentinian outbreak isolates belonged to distinct sublineages and had different epidemiologic origins.

Conclusions

Latin America contains novel genetic diversity of S. sonnei that is relevant on a global scale and commonly exhibits multidrug resistance. Retrospective passive surveillance with WGS has utility for informing treatment, identifying regionally epidemic sublineages and providing a framework for interpretation of prospective, locally sequenced outbreaks.

Multilateral spectral radiance factor scale comparison

The field of spectral radiance factor (SRF) measurements has seen growing interest in recent years. Scale conformity has so far only been established between the national metrology institutes (NMIs) of Germany and the USA. This study aims at a bigger, multilateral scale comparison. For this purpose, a total of six NMIs participated in a scale comparison of goniospectrophotometers based on neutral and colored diffusely reflecting ceramics samples. In addition, two universities, providing a home-built gonioreflectometer and two widely used commercially available color measurement instruments, respectively, were involved. The wavelength range of the scale comparison covers the visible wavelength range from 380 nm to 780 nm. Results indicate systematic issues and that the uncertainty evaluation of the NMIs requires further work; although for the greatest part of the covered spectral range the agreement is good.

The Survival of Motor Neuron Protein Acts as a Molecular Chaperone for mRNP Assembly

Spinal muscular atrophy (SMA) is a motor neuron disease caused by reduced levels of the survival of motor neuron (SMN) protein. SMN is part of a multiprotein complex that facilitates the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs). SMN has also been found to associate with mRNA-binding proteins, but the nature of this association was unknown. Here, we have employed a combination of biochemical and advanced imaging methods to demonstrate that SMN promotes the molecular interaction between IMP1 protein and the 3' UTR zipcode region of β-actin mRNA, leading to assembly of messenger ribonucleoprotein (mRNP) complexes that associate with the cytoskeleton to facilitate trafficking. We have identified defects in mRNP assembly in cells and tissues from SMA disease models and patients that depend on the SMN Tudor domain and explain the observed deficiency in mRNA localization and local translation, providing insight into SMA pathogenesis as a ribonucleoprotein (RNP)-assembly disorder.

Customizing plasmonic diffraction patterns by laser interference

This work reports a versatile and efficient production of periodic microstructures surrounded by metallic alloy nanoparticles supported on glass with customized visible diffraction patterns by using the technique of phase mask laser interference.

Serratia liquefaciens Infection of a Previously Excluded Popliteal Artery Aneurysm

Introduction

Popliteal artery aneurysms (PAAs) are rare in the general population, but they account for nearly 70% of peripheral arterial aneurysms. There are several possible surgical approaches including exclusion of the aneurysm and bypass grafting, or endoaneurysmorrhaphy and interposition of a prosthetic conduit. The outcomes following the first approach are favorable, but persistent blood flow in the aneurysm sac has been documented in up to one third of patients in the early post-operative setting. Complications from incompletely excluded aneurysms include aneurysm enlargement, local compression symptoms, and sac rupture. Notably infection of a previously excluded and bypassed PAA is rare. This is the third reported case of PAA infection after exclusion and bypass grafting and the first due to Serratia liquefaciens.

Methods

Relevant medical data were collected from the hospital database.

Results

This case report describes a 54 year old male patient, diagnosed with acute limb ischaemia due to a thrombosed PAA, submitted to emergency surgery with exclusion and venous bypass. A below the knee amputation was necessary 3 months later. Patient follow-up was lost until 7 years following surgical repair, when he was diagnosed with aneurysm sac infection with skin fistulisation. He had recently been diagnosed with alcoholic hepatic cirrhosis Child–Pugh Class B. The patient was successfully treated by aneurysm resection, soft tissue debridement and systemic antibiotics.

Conclusion

PAA infection is a rare complication after exclusion and bypass procedures but should be considered in any patient with evidence of local or systemic infection. When a PAA infection is diagnosed, aneurysmectomy, local debridement, and intravenous antibiotic therapy are recommended. The “gold standard” method of PAA repair remains controversial. PAA excision or endoaneurysmorrhaphy avoids complications from incompletely excluded aneurysms, but is associated with a high risk of neurological damage.

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Popliteal artery aneurysms (PAAs) are the most common cause of non-traumatic leg amputation.

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Potential complications from PAA exclusion are aneurysm enlargement, local compression symptoms, sac rupture, and infection.

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Infection of a previously excluded and bypassed popliteal artery aneurysm is exceedingly rare.

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This is the third case of excluded aneurysm infection, and the first by the Serrate genus.

Color characterization of coatings with diffraction pigments

Coatings with diffraction pigments present high iridescence, which needs to be characterized in order to describe their appearance. The spectral bidirectional reflectance distribution functions (BRDFs) of six coatings with SpectraFlair diffraction pigments were measured using the robot-arm-based goniospectrophotometer GEFE, designed and developed at CSIC. Principal component analysis has been applied to study the coatings of BRDF data. From data evaluation and based on theoretical considerations, we propose a relevant geometric factor to study the spectral reflectance and color gamut variation of coatings with diffraction pigments. At fixed values of this geometric factor, the spectral BRDF component due to diffraction is almost constant. Commercially available portable goniospectrophotometers, extensively used in several industries (automotive and others), should be provided with more aspecular measurement angles to characterize the complex reflectance of goniochromatic coatings based on diffraction pigments, but they would not require either more than one irradiation angle or additional out-of-plane geometries.

The importance of protection glasses during neuroangiographies: A study on radiation exposure at the lens of the primary operator

BACKGROUND

In interventional neuroradiology, few operators routinely use radiation protection glasses. Moreover, in most centers, radiation dose data only accounts for whole body dose without specific information on lens dose. In 2012, the International Commission on Radiological Protection advised that the threshold limit value for the lens should be 20 mSv/year instead of the previous 150 mSv/year limit. The purpose of this study was to compare the radiation dose in the operator's lens during real diagnostic and interventional neuroangiographies, either using or without lead protection glasses.

METHODS

Using the Educational Direct Dosimeter (EDD30 dosimeter), accumulated radiation dose in the lens was measured in 13 neuroangiographies: seven diagnostic and six interventional. Operators with and without radiation protection glasses were included and the sensor was placed near their left eye, closest to the radiation beam.

RESULTS

Without glasses, the corrected mean dose of radiation in the lens was 8.02 µSv for diagnostic procedures and 168.57 µSv for interventional procedures. Using glasses, these values were reduced to 1.74 µSv and 33.24 µSv, respectively.

CONCLUSION

Considering 20 mSv as the suggested annual limit of equivalent dose in the lens, neuroradiologists may perform up to 2,494 diagnostic procedures per year without protecting glasses, a number that increases to 11,494 when glasses are used consistently. Regarding intervention, a maximum of 119 procedures per year is advised if glasses are not used, whereas up to 602 procedures/year may be performed using this protection. Therefore, neuroradiologists should always wear radiation protection glasses.

Thermodynamic temperature assignment to the point of inflection of the melting curve of high-temperature fixed points

The thermodynamic temperature of the point of inflection of the melting transition of Re-C, Pt-C and Co-C eutectics has been determined to be 2747.84 ± 0.35 K, 2011.43 ± 0.18 K and 1597.39 ± 0.13 K, respectively, and the thermodynamic temperature of the freezing transition of Cu has been determined to be 1357.80 ± 0.08 K, where the ± symbol represents 95% coverage. These results are the best consensus estimates obtained from measurements made using various spectroradiometric primary thermometry techniques by nine different national metrology institutes. The good agreement between the institutes suggests that spectroradiometric thermometry techniques are sufficiently mature (at least in those institutes) to allow the direct realization of thermodynamic temperature above 1234 K (rather than the use of a temperature scale) and that metal-carbon eutectics can be used as high-temperature fixed points for thermodynamic temperature dissemination. The results directly support the developing mise en pratique for the definition of the kelvin to include direct measurement of thermodynamic temperature.

The importance of protection glasses during neuroangiographies: A study on radiation exposure at the lens of the primary operator

Background

In interventional neuroradiology, few operators routinely use radiation protection glasses. Moreover, in most centers, radiation dose data only accounts for whole body dose without specific information on lens dose. In 2012, the International Commission on Radiological Protection advised that the threshold limit value for the lens should be 20 mSv/year instead of the previous 150 mSv/year limit. The purpose of this study was to compare the radiation dose in the operator’s lens during real diagnostic and interventional neuroangiographies, either using or without lead protection glasses.

Methods

Using the Educational Direct Dosimeter (EDD30 dosimeter), accumulated radiation dose in the lens was measured in 13 neuroangiographies: seven diagnostic and six interventional. Operators with and without radiation protection glasses were included and the sensor was placed near their left eye, closest to the radiation beam.

Results

Without glasses, the corrected mean dose of radiation in the lens was 8.02 µSv for diagnostic procedures and 168.57 µSv for interventional procedures. Using glasses, these values were reduced to 1.74 µSv and 33.24 µSv, respectively.

Conclusion

Considering 20 mSv as the suggested annual limit of equivalent dose in the lens, neuroradiologists may perform up to 2,494 diagnostic procedures per year without protecting glasses, a number that increases to 11,494 when glasses are used consistently. Regarding intervention, a maximum of 119 procedures per year is advised if glasses are not used, whereas up to 602 procedures/year may be performed using this protection. Therefore, neuroradiologists should always wear radiation protection glasses.

Magnetic resonance correlation of iron content with neuromelanin in the substantia nigra of early-stage Parkinson's disease

BACKGROUND AND PURPOSE

Magnetic resonance (MR) studies have demonstrated a significant reduction of neuromelanin in the substantia nigra (SN) of Parkinson's disease (PD) patients with high accuracy for differential diagnosis compared to non-PD controls and essential tremor. However, studies state that not knowing how paramagnetic effects of iron influence neuromelanin signal is a limitation. In this study a neuromelanin-sensitive MR sequence was combined with T2* relaxometry iron quantification analysis to study the SN of early-stage PD patients to investigate the correlation between these parameters.

METHODS

The inclusion criteria were untreated de novo PD patients and a 2-5 year disease duration (early PD); in addition, age-matched controls were enrolled. These were studied at 3.0 T with a high-resolution T1-weighted MR sequence to visualize neuromelanin and a relaxometry sequence for iron quantification. The primary outcome was the correlation of the width of the neuromelanin high signal region and the T2* values in the lateral, central and medial segments of the SN.

RESULTS

Very weak correlations of T2* values with neuromelanin width, positive for global and negative for the medial and lateral SN segments, were found in both PD groups and control subjects. The SN neuromelanin width was markedly reduced in the de novo and early PD groups compared with controls in all SN segments, but no significant difference in T2* values was found between the groups.

CONCLUSIONS

The SN neuromelanin signal does not have a significant correlation with iron content in PD patients or controls. The neuromelanin MR signal reduction in PD does not seem to be significantly influenced by paramagnetic iron effects.

Implementation and performance of an in-line incomplete Stokes polarimeter based on a single biaxial crystal

Due to the increasing interest of polarimetric information in numerous applications, different Stokes polarimeter designs are provided in the literature for the measure of light beam polarization. Recently, the concept of polarimeters based on the conical refraction (CR) phenomenon, occurring in biaxial crystals, was proposed. CR polarimeters are snapshot polarimeters that allow controlling the volume of data redundancy without an increase in the acquisition time. We present the implementation, calibration, and analysis of an incomplete CR-polarimeter optimized for the measure of linear polarizations. A simpler and cheaper experimental configuration is achieved, if compared with other polarimeters proposed in the literature. The suitability of the polarimeter is experimentally demonstrated and some of its benefits, such as its performance in low-intensity conditions, are discussed.