User-friendly one-step disposable signal-on bioassay for glyphosate detection in water samples.

The onsite detection of glyphosate requires an easy-to-handle, low-cost and disposable assay for untrained users as requested by the ASSURED guidelines. A new strategy based on the expression of fusion proteins is proposed here. A glyphosate oxidase derived from Bacillus subtilis and the 6E10 variant of the dye peroxidase from Pseudomonas putida, both fused with the carbohydrate binding module (CBM) 3a from Clostridium thermocellum, were designed and expressed, leading to GlyphOx-CBM and 6E10-CBM. Cell lysates were used to immobilise both enzymes on cotton buds' heads without any purification. The cotton buds exhibit glyphosate oxidase activity when dipped into a glyphosate-contaminated water sample containing the 6E10-CBM chromogenic substrates. The chromophore could be quantified both in the solution and on the cotton buds' heads. Photography followed by image analysis allows to detect glyphosate with a linear range of 0.25-2.5 mM and a limit of detection (LoD) of 0.12 mM. When the chromogenic substrates are replaced by luminol, the chemiluminescence reaction allows the detection of glyphosate with a linear range of 2-500 µM and a LoD of 0.45 µM. No interference was observed using glyphosate analogues (glycine, sarcosine, aminomethylphosphonic acid) or other herbicides used in a mixture. Only cysteine was found to inhibit 6E10-CBM. Two river waters spiked with glyphosate lead to recoveries of 64-131%. This work describes a very easy-to-handle and inexpensive signal-on bioassay for glyphosate detection in real surface water samples.

Prompt Response of the Dayside Magnetosphere to Discrete Structures Within the Sheath Region of a Coronal Mass Ejection.

A sequence of discrete solar wind structures within the sheath region of an interplanetary coronal mass ejection on November 6, 2015, caused a series of compressions and releases of the dayside magnetosphere. Each compression resulted in a brief adiabatic enhancement of ions (electrons) driving bursts of electromagnetic ion cyclotron (EMIC; whistler mode chorus) wave growth across the dayside magnetosphere. Fine-structured rising tones were observed in the EMIC wave bursts, resulting in nonlinear scattering of relativistic electrons in the outer radiation belt. Multipoint observations allow us to study the spatial structure and evolution of these sheath structures as they propagate Earthward from L1 as well as the spatio-temporal characteristics of the magnetospheric response. This event highlights the importance of fine-scale solar wind structure, in particular within complex sheath regions, in driving dayside phenomena within the inner magnetosphere.

[Atypical hand, foot and mouth disease in adults: A note on 6 cases]. / Syndrome main-pied-bouche atypique de l'adulte : à propos de 6 observations.

INTRODUCTION: Hand, foot and mouth disease (HFMD) is form of viral dermatosis well known among the pediatric population, in whom it has a typical presentation. However, it is less common in adults, with a more heterogeneous presentation, potentially making diagnosis extremely challenging for the clinician. PATIENTS AND METHODS: This was a retrospective case series from 2013 to 2018 of HFMD in adults, with all cases being confirmed by cutaneous polymerase chain reaction (PCR). We studied the clinical, epidemiological and viral characteristics of each patient. RESULTS: This series of 6 cases comprised 4 men and 2 women, with a mean age of 42.5 years. Five patients presented extended purpuric lesions, four had bullous lesions, and three showed cutaneous signs without any mucosal lesions. Extended lesions on the trunk were found in four patients. One patient presented rosette-shaped pustular lesions on the limbs, one had eczema-like lesions on the scalp, and one presented extended purpuric lesions on the soles. DISCUSSION: These different cases of adult HFMD raise questions about differential diagnosis in relation to other acute cutaneous and mucous diseases. It is essential to be aware of these different types of presentation of the disease in order to determine the diagnosis and discuss preventive measures.

[Cholesterol crystal embolism mimicking a DRESS]. / Des embolies de cristaux de cholestérol mimant un DRESS.

INTRODUCTION: Clinical presentation of cholesterol crystal embolism (CCE) can be dermatologic when cholesterol crystals become lodged in small cutaneous arteries resulting in ischemia. We report a case of CCE with erythroderma misleading to a diagnostic of drug reaction with eosinophilia and systemic symptoms (DRESS). CASE REPORT: A 66 year-old woman presented with erythroderma few months after initiation of allopurinol. Acute renal failure was present with elevation in plasma creatinine concentration (523µmol/L) and hypereosinophilia (HE) (5666/mm3). Finally, the REGISCAR score helped to rule out DRESS diagnostic. Past blood-count tests were analyzed revealing chronic HE present before allopurinol initiation. Renal biopsy identified CCE. CONCLUSION: This case is the first to report a DRESS like presentation of CCE. Clinical findings are secondary to HE and not to occlusion of cutaneous arteries.

Statistical Properties of Electron Curtain Precipitation Estimated With AeroCube-6.

Curtain precipitation is a recently discovered stationary, persistent, and latitudinally narrow electron precipitation phenomenon in low Earth orbit. Curtains are observed over consecutive passes of the dual AeroCube-6 CubeSats while their in-track lag varied from a fraction of a second to 65 s, with dosimeters that are sensitive to >35-keV electrons. This study uses the AeroCube-6 mission to quantify the statistical properties of 1,634 curtains observed over 3 years. We found that many curtains are narrower than 10 km in the latitudinal direction with 90% narrower than 20 km. We examined the geographic, magnetic local time, and geomagnetic dependence of curtains. We found that curtains are observed in the late-morning and premidnight magnetic local times, with a higher occurrence rate at premidnight, and curtains are observed more often during times of enhanced Auroral Electrojet. We found a few curtains in the bounce loss cone region above the North Atlantic, whose electrons were continuously scattered for at least 6 s. Such observations suggest that continuous curtain precipitation may be a significant loss of >35-keV electrons from the magnetosphere into the atmosphere. We hypothesize that the curtains observed in the bounce loss cone were accelerated by parallel electric fields, and we show that this mechanism is consistent with the observations.

[Amoxicillin-induced skin rash sparing a plaque of erythema migrans: Renbök phenomenon: Case report and literature review]. / Toxidermie à l'amoxicilline épargnant une plaque d'érythème migrant : phénomène de Renbök et revue de la littérature.

INTRODUCTION: Renbök phenomenon describes the inhibition of a lesion when a different one appears. We describe the first case of Renbök phenomenon occurring in a context of erythema migrans (EM) spared by an amoxicillin-induced skin rash and we also present a literature review. CASE REPORT: A 60-year-old patient was treated with amoxicillin for EM on the right knee and subsequently developed generalized erythema as a result of an antibiotic-induced skin rash, with sparing of the area previously affected by EM. Renbök phenomenon was diagnosed. DISCUSSION: In 1981, Cochran et al. first described a maculopapular drug reaction, which spared the sites of previous X irradiation for a tumor. Since then, nearly 40 cases have been reported, mostly describing patient with alopecia areata of the scalp with hair growth within plaques of psoriasis. One of the mechanisms suggested is a role played by cytokine cross-regulation in competition among distinct immune responses. CONCLUSION: We report the first case of Renbök phenomenon involving EM spared by a drug reaction. This phenomenon provides an insight into inflammatory response competition within a single patient.

Upper limit on the inner radiation belt MeV electron intensity.

No instruments in the inner radiation belt are immune from the unforgiving penetration of the highly energetic protons (tens of MeV to GeV). The inner belt proton flux level, however, is relatively stable; thus, for any given instrument, the proton contamination often leads to a certain background noise. Measurements from the Relativistic Electron and Proton Telescope integrated little experiment on board Colorado Student Space Weather Experiment CubeSat, in a low Earth orbit, clearly demonstrate that there exist sub-MeV electrons in the inner belt because their flux level is orders of magnitude higher than the background, while higher-energy electron (>1.6 MeV) measurements cannot be distinguished from the background. Detailed analysis of high-quality measurements from the Relativistic Electron and Proton Telescope on board Van Allen Probes, in a geo-transfer-like orbit, provides, for the first time, quantified upper limits on MeV electron fluxes in various energy ranges in the inner belt. These upper limits are rather different from flux levels in the AE8 and AE9 models, which were developed based on older data sources. For 1.7, 2.5, and 3.3 MeV electrons, the upper limits are about 1 order of magnitude lower than predicted model fluxes. The implication of this difference is profound in that unless there are extreme solar wind conditions, which have not happened yet since the launch of Van Allen Probes, significant enhancements of MeV electrons do not occur in the inner belt even though such enhancements are commonly seen in the outer belt. KEY POINTS: Quantified upper limit of MeV electrons in the inner beltActual MeV electron intensity likely much lower than the upper limitMore detailed understanding of relativistic electrons in the magnetosphere.

An impenetrable barrier to ultrarelativistic electrons in the Van Allen radiation belts.

Early observations indicated that the Earth's Van Allen radiation belts could be separated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. Subsequent studies showed that electrons of moderate energy (less than about one megaelectronvolt) often populate both zones, with a deep 'slot' region largely devoid of particles between them. There is a region of dense cold plasma around the Earth known as the plasmasphere, the outer boundary of which is called the plasmapause. The two-belt radiation structure was explained as arising from strong electron interactions with plasmaspheric hiss just inside the plasmapause boundary, with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location. Recent observations have revealed unexpected radiation belt morphology, especially at ultrarelativistic kinetic energies (more than five megaelectronvolts). Here we analyse an extended data set that reveals an exceedingly sharp inner boundary for the ultrarelativistic electrons. Additional, concurrently measured data reveal that this barrier to inward electron radial transport does not arise because of a physical boundary within the Earth's intrinsic magnetic field, and that inward radial diffusion is unlikely to be inhibited by scattering by electromagnetic transmitter wave fields. Rather, we suggest that exceptionally slow natural inward radial diffusion combined with weak, but persistent, wave-particle pitch angle scattering deep inside the Earth's plasmasphere can combine to create an almost impenetrable barrier through which the most energetic Van Allen belt electrons cannot migrate.

DNA biosensor/biochip for multiplex blood group genotyping.

At present, 33 blood groups representing over 300 antigens are listed by the International Society of Blood Transfusion (ISBT). Most of them result from a single nucleotide polymorphism (SNP) in the corresponding DNA sequence, i.e. approx. 200 SNPs. In immunohematology laboratories, blood group determination is classically carried out by serological tests, but these have some limitations, mostly in term of multiplexing and throughput. Yet, there is a growing need of extended blood group typing to prevent alloimmunization in transfused patients and transfusion accidents. The knowledge of the molecular bases of blood groups allows the use of molecular biology methods within immunohematology laboratories. Numerous assays focused on blood group genotyping were developed and described during the last 10 years. Some of them were real biochips or biosensors while others were more characterized by the particular molecular biology techniques they used, but all were intending to produce multiplex analysis. PCR techniques are most of the time used followed by an analytical step involving a DNA biosensor, biochip or analysis system (capillary electrophoresis, mass spectrometry). According to the method used, the test can then be classified as low-, medium- or high-throughput. There are several companies which developed platforms dedicated to blood group genotyping able to analyze simultaneously various SNPs or variants associated with blood group systems. This review summarizes the characteristics of each molecular biology method and medium-/high-throughput platforms dedicated to the blood group genotyping.

Intestinal infection with Trichinella spiralis induces distinct, regional immune responses.

The aim of this study was to evaluate differences between the small and large intestines (SI and LI) with regard to colonization and immunity during infection with Trichinella spiralis. In orally infected C57BL/6 mice, the gender ratios of worms differed among the SI, cecum, and LI. Mucosal mastocytosis developed in the SI but not in the LI, consistent with reduced IL-9 and IL-13 production by explants from the LI. Despite these differences, worms were cleared at the same rate from both sites. Furthermore, IL-10 production was reduced in the LI, yet it was instrumental in limiting local inflammation. Finally, passive immunization of rat pups with tyvelose-specific antibodies effectively cleared fist-stage larvae from all intestinal regions. We conclude that despite regional differences in immune responsiveness and colonization, immune mechanisms that clear T. spiralis operate effectively throughout the intestinal tract.

Multiplexed immunoassay for the rapid detection of anti-tumor-associated antigens antibodies.

TAAs (tumor-associated antigens) microarrays were designed to detect auto-antibodies directly in patient sera. Twelve different probes were chosen according to their described occurrence in cancer pathologies (Cyclin B1, Cyclin D1, Complement factor H, c-myc, IMP1, p53, p62, survivin, Her2/neu, Koc, NY-ESO-1 and PSA). Microarrays of these 12 proteins were immobilized within the nitrocellulose/cellulose acetate membrane of a 96-well filtering microtiter plate bottom. The captured auto-antibodies were detected using a staining approach based on alkaline phosphatase labeling. Thus, the presence of specific auto-antibodies in samples was visualized through the positive staining of the corresponding TAA spots. The TAA HiFi microarrays were shown to be able to capture specific purified anti-TAA antibodies. In real samples, 9 proteins from the 12 TAAs panel were shown to generate specific signal and 5 antigens (p53, NY-ESO-1, IMP1, cyclin B1 and c-myc) were shown to have interaction with more than 10% of the positive sera from cancer patients. This protein subpanel was proven to be able to detect 72.2% of the cancer patients tested (within a 34 panel of 18 patients and 16 healthy donors).

Community perceptions of bloody diarrhoea in an urban slum in South Asia: implications for introduction of a Shigella vaccine.

Understanding local perceptions of disease causation could help public health officials improve strategies to prevent bloody diarrhoea. A cross-sectional survey was conducted in Dhaka, Bangladesh to elicit community beliefs about the causes of and prevention strategies for bloody diarrhoea. Between March and June 2003, we interviewed 541 randomly selected respondents. Overall, 507 (93%) respondents perceived that a vaccine could prevent bloody diarrhoea. If a vaccine provided lifetime protection, 445 (83%) respondents stated that they would opt to get the vaccine and would pay a median of $0·05 (range U.S.$0·01-0·15) for it, equivalent to <1% of their median weekly income. There was almost universal perception that an effective vaccine to prevent bloody diarrhoea was highly beneficial and acceptable. While respondents valued a vaccine for prevention of bloody diarrhoea, they were only willing to pay minimally for it. Therefore, achieving a high rate of Shigella vaccine coverage may require subsidy of vaccine purchase.

Child supervision practices for drowning prevention in rural Bangladesh: a pilot study of supervision tools.

BACKGROUND: Injuries are an increasing child health concern and have become a leading cause of child mortality in the 1-4 years age group in many developing countries, including Bangladesh. METHODS: Household observations during 9 months of a community-based pilot of two supervision tools-a door barrier and a playpen-designed to assess their community acceptability in rural Bangladesh are reported in this article. RESULTS: Statistical analysis of 2694 observations revealed that children were directly supervised or protected by a preventive tool in 96% of visits. Households with a supervision tool had a significantly lower proportion of observations with the child unsupervised and unprotected than households without a tool. Families that received a playpen had 6.89 times the odds of using it at the time of the visit than families that received a door barrier. CONCLUSIONS: Interventions such as the playpen, when introduced to households through community-based programs, are accepted by parents. Field trials are urgently needed to establish the effectiveness of barrier-based interventions at reducing under-five drowning mortality rates in low-income countries like Bangladesh.