Introduction
Antiphospholipid syndrome (APS) is associated with greater atherothrombotic risk and endothelial dysfunction, suggesting that endothelial glycocalyx is impaired in this disease.
...Objectives
The aim was to investigate the endothelial glycocalyx and the relationship between glycocalyx markers, endothelial dysfunction parameters and atherosclerotic markers in APS.
Methods
A total of 15 primary arterial APS patients and healthy controls were included in the study. Glycocalyx was assessed in both groups by sublingual sidestream dark field imaging and syndecan-1 plasma level. Endothelial function was evaluated by brachial artery flow-mediated dilatation (FMD) and early atherosclerosis by carotid intima media thickness (IMT). Thrombotic profile was also performed by measuring the plasma level of the tissue factor (TF).
Results
APS patients had significantly increased syndecan-1 plasma level 38.6 ± 5.0 pg/ml vs. 19.1 ± 3.5 pg/ml; p < 0.01 and a reduced glycocalyx thickness 0.26 ± 0.03 µm vs. 0.75 ± 0.07 µm; p < 0.01 compared with control. FMD was impaired in APS patients compared with control, 5.68% ± 0.42 vs. 8.29 ± 0.30, p < 0.01, respectively. IMT was significantly increased in APS patients compared with control, 0.52 ± 0.13 mm vs. 0.40 ± 0.06 mm, p < 0.01, respectively. Soluble TF, thiobarbituric acid-reactive substances levels were increased in the sera from APS patients compared with control.
Conclusions
This preliminary study supports, for the first time, that in APS patients endothelial glycocalyx is impaired, which could lead to thrombosis, endothelial dysfunction and early atherosclerosis.
The cosmic ray spectrum has been shown to extend well beyond 10
20 eV. With nearly 20 events observed in the last 40 years, it is now established that particles are accelerated or produced in the ...universe with energies near 10
21 eV at the production site. In all production models neutrinos and photons are part of the cosmic ray flux. In acceleration models (bottom-up models), they are produced as secondaries of the possible interactions of the accelerated charged particle; in direct production models (top-down models) they are a dominant fraction of the decay chain. In addition, hadrons above the GZK threshold energy will also produce, along their path in the Universe, neutrinos and photons as secondaries of the pion photo-production processes. Therefore, photons and neutrinos are very distinctive signatures of the nature and distribution of the potential sources of ultrahigh energy cosmic rays. In the following we describe the tau neutrino detection and identification capabilities of the Auger Observatory. We show that in the range 3×10
17–3×10
20 eV the Auger effective aperture reaches a few tenths of km
2
sr, making the Observatory sensitive to fluxes as low as a few tau neutrinos per km
2
sr
year. In the hypothesis of ν
μ→ν
τ oscillations with full mixing, this sensitivity allows to a probe of the GZK cutoff as well as providing model independent constraints on the mechanisms of production of ultrahigh energy cosmic rays.
The COVID-19 pandemic is associated with a high incidence of venous thromboembolism questioning the utility of a systematic screening for deep venous thrombosis (DVT) in hospitalised patients.
In ...this prospective bicentric controlled study, 4-point ultrasound using a pocket device was used to screen for DVT, in patients with SARS-CoV-2 infection and controls admitted for acute medical illness not related to COVID-19 hospitalised in general ward, in order to assess the utility of a routine screening and to estimate the prevalence of VTE among those patients.
Between April and May 2020, 135 patients were screened, 69 in the COVID+ group and 66 in the control one. There was no significant difference in the rate of proximal DVT between the two groups (2.2% vs. 1.5%; P=0.52), despite the high rate of PE diagnosed among COVID-19 infected patients (10.1% vs. 1.5%, P=0.063). No isolated DVT was detected, 37.5% of PE was associated with DVT. Mortality (7.2% vs. 1.5%) was not different (P=0.21) between COVID-19 patients and controls.
The systematic screening for proximal DVT was not found to be relevant among COVID-19 patients hospitalized in general ward despite the increase of VTE among this population. Further studies are needed to confirm the hypothesis of a local pulmonary thrombosis which may lead to new therapeutic targets.
Ultra-high energy cosmic rays generate extensive air showers in Earth’s atmosphere. A standard approach to reconstruct the energy of an ultra-high energy cosmic rays is to sample the lateral profile ...of the particle density on the ground of the air shower with an array of surface detectors.
For cosmic rays with large inclinations, this reconstruction is based on a model of the lateral profile of the muon density observed on the ground, which is fitted to the observed muon densities in individual surface detectors. The best models for this task are derived from detailed Monte-Carlo simulations of the air shower development. We present a phenomenological parametrization scheme which allows to derive a model of the average lateral profile of the muon density directly from a fit to a set of individual Monte-Carlo simulated air showers. The model reproduces the detailed simulations with a high precision. As an example, we generate a muon density model which is valid in the energy range 10
18
eV
<
E
<
10
20
eV and the zenith angle range
60
°
<
θ
<
90
°
.
We will further demonstrate a way to speed up the simulation of such muon profiles by three orders of magnitude, if only the muons in the shower are of interest.
Hemolacria is a rare hemorrhagic syndrome characterized by bloody tears. The most common etiologies are inflammation, infection or laceration. However, other rarer diseases may also cause this ...clinical manifestation.
We describe the case of a 14-year-old male patient hospitalized for hemolacria. A history of von Willebrand disease was present in his family, diagnosed in his mother and sister, but absent in our patient. A vitamin C dosage was obtained in our patient and revealed scurvy consecutive to malnutrition. After having excluded other bleeding symptoms like bruises we retained vitamin C deficiency as the etiology of the hemorrhagic syndrome.
Bloody tears are a rare clinical manifestation and the etiology may be difficult to determine. Bloody tears are a rare clinical manifestation of hemorrhagic syndrome. To determine the underlying etiology, screening should consider all possible causes including the rarest.
A 31-year-old man with mild hemophilia B developed a herniated disc treated with prednisolone for back pain. Surprisingly, hemostasis result tests performed before epidural infiltration were a normal ...activated partial thrombin time at 36.1 s. (normal range 27.9–37.7 s.) and factor IX (FIX) level 76% (normal range>70%), 13 days after prednisolone introduction. After a second control with a normal FIX level and a second genetic confirmation of hemophilia, no FIX concentrates was administered to perform the infiltration, which occurred without hemorrhagic complication. This new case of FIX normalization showed the necessity to have a perfect knowledge of patient’s treatment to avoid misdiagnosis and a temporary normal hemostasis permit to perform epidural infiltration without replacement therapy.
Factor (F)XI deficiency is a rare bleeding disorder with a poor correlation between bleeding tendency and FXI level. Management of pregnant women with FXI deficiency is not clearly established, ...especially regarding neuraxial analgesia (NA).
A retrospective multicenter observational study was conducted in French hemostasis centers on pregnant women with FXI of <60 IU/dL.
Data to report were (i) FXI levels before pregnancy and at time of delivery, (ii) type of NA and delivery management modalities, and (iii) possible complications related to NA and bleeding complications.
Three hundred fourteen pregnancies in patients with FXI deficiency of <60 IU/dL were reported (from 20 centers); among them, 199 NA procedures have been completed (137 epidurals and 61 spinals, 1 had both). The period of childbirth was mostly from 2014 to 2020 (281/314; 89.5%). Congenital FXI deficiency was established with certainty by investigators in 32.8% patients (n = 103). Previous bleedings were described in 20.4% of the patients (64/314; 45.3% cutaneous, 31.3% gynecologic, and 15.6% postsurgical). Thirteen deliveries had an NA procedure with FXI of <30 IU/dL, 42 with FXI of 30-40 IU/dL, and 118 with FXI of 40-60 IU/dL. Median FXI levels at delivery in the epidural and spinal groups were not significantly different but were significantly lower in the group without NA by medical staff contraindications. There were no complications related to NA. A 17.5% postpartum hemorrhage or excessive postpartum bleeding incidence was reported, which is consistent with previous data.
Our data support the use of a 30 IU/dL FXI threshold for NA, as suggested by the French proposals published in August 2023.
•Factor (F)XI deficiency is a rare bleeding disorder with a poor correlation between bleeding tendency and FXI level. The management of FXI deficiency in pregnant women is not yet established, particularly with regard to neuraxial analgesia (NA).•We conducted an anonymous retrospective study from 2009 to 2020 of women with FXI activity level below 60 IU/dL before pregnancy and/or below 60 IU/dL at time of delivery in 20 French centers. Of the 314 reported pregnancies, 199 NA procedures were completed (137 epidurals and 61 spinals, 1 had both). There were no complications related to NA, and 173 NAs were allowed with known FXI levels at time of delivery ranging from 17 to 60 IU/dL with a mean FXI level at time of delivery of 44.2 ± 9.5 IU/dL.•Our results support the use of a 30 IU/dL threshold for NA (all types of NA in women with no bleeding history: spinal and epidural) at time of procedure or for catheter removal. However, we also reported a 17.5% incidence of postpartum hemorrhage or excessive postpartum bleeding, which is in accordance with previous studies. Our results now need to be confirmed by large prospective studies.
Antiphospholipid syndrome (APS) is a clinico-biological syndrome, which associates vascular injury and persisting antiphospholipid antibodies (aPL). Patients with clinical symptoms of APS but without ...aPL are defined as "seronegative APS" (SNAPS). The aim of this study was to evaluate antiphosphatidylethanolamine antibody (aPE) investigation in patients with SNAPS suspicion.
This retrospective study was conducted in patients with SNAPS suspicion. A homemade enzyme-linked immunosorbent assay (ELISA) was used to search for aPE. The results of this homemade method were compared with those from a global screening ELISA.
Two hundred twenty-eight patients with SNAPS suspicion were included. Among them, 58.3% had a thrombotic event. The homemade ELISA found positive persisting aPE in 23 patients (10%): 15 with a thrombotic event, 6 with obstetrical morbidity and 2 with a combined event. The global screening ELISA was positive in only 11 of these 23 patients (47.8%).
These results suggest the implication of aPE in SNAPS.
The collection of a statistically significant number detected of cosmic rays with energy above 1017 to 1018 eV requires widely-spaced particle detectors at the ground level to detect the extensive ...air showers induced in the atmosphere. The air-shower sizes, proxies of the primary energies, are then estimated by fitting the observed signals to a functional form for expectations so as to interpolate the signal at a reference distance. The functional form describes the rapid falloff of the expected signal with the distance from the shower core, using typically two logarithmic slopes to account for the short-range and long-range decreases of signals. The uncertainties associated to the air-shower sizes are determined under the assumption of a quadratic dependence of the log-likelihood on the fitted parameters around the minimum, so that a meaningful variance–covariance matrix is provided. In this paper, we show that for an event topology where one signal is much larger than the others, the quadratic dependence of the fitted function around the minimum is a poor approximation that leads to an inaccurate estimate of the uncertainties. To restore a quadratic shape, we propose to use the polar coordinates around the detector recording the largest signal, projected onto the plane of the shower front, to define the likelihood function in terms of logarithmic polar distances, polar angles and logarithmic shower sizes as free parameters. We show that a meaningful variance–covariance matrix is then recovered in the new coordinate system, as the dependence of the fitted function on the modified parameters is properly approximated by a quadratic function. The use of the uncertainties in the new coordinate system for subsequent high-level analyses is illustrated.
We present an alternative implementation of the Kalman filter employed for track fitting within the LHCb experiment. It uses simple parametrizations for the extrapolation of particle trajectories in ...the field of the LHCb dipole magnet and for the effects of multiple scattering in the detector material. A speedup of more than a factor of four is achieved while maintaining the quality of the estimated track quantities. This Kalman filter implementation could be used in the purely software-based trigger of the LHCb upgrade.
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