Performances, feasibility and acceptability of nasopharyngeal swab, saliva and oral-self sampling swab for the detection of severe acute respiratory syndrome coronavirus 2.

Molecular diagnosis on nasopharyngeal swabs (NPS) is the current standard for COVID-19 diagnosis, but saliva may be an alternative specimen to facilitate access to diagnosis. We compared analytic performances, feasibility and acceptability of NPS, saliva, and oral-self sampling swab for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A prospective, multicenter study was conducted in military hospitals in France among adult outpatients attending COVID-19 diagnosis centers or hospitalized patients. For each patient, all samples were obtained and analyzed simultaneously with RT-PCR or transcription-mediated amplification method. Clinical signs, feasibility, and acceptability for each type of sample were collected. A total of 1220 patients were included, corresponding to 1205 NPS and saliva and 771 OS. Compared to NPS, the sensitivity, specificity, and kappa coefficient for tests performed on saliva were 87.8% (95% CI 83.3-92.3), 97.1% (95% CI 96.1-98.1), and 0.84 (95% CI 0.80-0.88). Analytical performances were better in symptomatic patients. Ct values were significantly lower in NPS than saliva. For OS, sensitivity was estimated to be 61.1% (95% CI 52.7-69.4) and Kappa coefficient to be 0.69 (95% CI 0.62-0.76). OS was the technique preferred by the patients (44.3%) before saliva (42.4%) and NPS (13.4%). Instructions were perceived as simple by patients (> 90%) for saliva and OS. Finally, the painful nature was estimated to be 0.9 for OS, on a scale from 0 to 10, and to be 5.3 for NPS. Performances of OS are not sufficient. Saliva is an acceptable alternative to NPS for symptomatic patient but the process required additional steps to fluidize the sample.

Dielectric Elastomer Generator with Improved Energy Density and Conversion Efficiency Based on Polyurethane Composites.

Dielectric elastomer generators (DEGs), which follow the physics of variable capacitors and harvest electric energy from mechanical work, have attracted intensive attention over the past decade. The lack of ideal dielectric elastomers, after nearly two decades of research, has become the bottleneck for DEGs' practical applications. Here, we fabricated a series of polyurethane-based ternary composites and estimated their potential as DEGs to harvest electric energy for the first time. Thermoplastic polyurethane (PU) with high relative permittivity (∼8) was chosen as the elastic matrix. Barium titanate (BT) nanoparticles and dibutyl phthalate (DBP) plasticizers, which were selected to improve the permittivity and mechanical properties, respectively, were blended into the PU matrix. As compared to pristine PU, the resultant ternary composite films fabricated through a solution casting approach showed enhanced permittivity, remarkably reduced elastic modulus, and relatively good electrical breakdown strength, dielectric loss, and strain at break. Most importantly, the harvested energy density of PU was significantly enhanced when blended with BT and DBP. A composite film containing 25 phr of BT and 60 phr of DBP with the harvested energy density of 1.71 mJ/cm3 was achieved, which is about 4 times greater than that of pure PU and 8 times greater than that of VHB adhesives. Remarkably improved conversion efficiency of mechano-electric energy was also obtained via cofilling BT and DBP into PU. The results shown in this work strongly suggest compositing is a very promising way to provide better dielectric elastomer candidates for forthcoming practical DEGs.

A Cross-Reactivity of Fenofibric Acid With MDMA DRI Assay.

BACKGROUND: Within the framework of routine fitness examinations, French Air Force military crew underwent urine testing for 3,4 methylenedioxymetamphetamine (MDMA [ecstasy]). The cross-reactivity of a dyslipidemic drug, fenofibrate, with an MDMA immunoassay was studied and confirmed on a large population sample. METHODS: A 3-year retrospective study was performed on the MDMA DRI Ecstasy Assay on the Unicel DXC 600. In the event of positive test result, a confirmatory testing was carried out by gas chromatography/mass spectrometry (GC/MS) to establish the presence of MDMA. When analysis by GC/MS did not confirm the presence of MDMA, a false-positive result was suspected and the samples were analyzed by high-performance liquid chromatography-mass spectrometry to identify a potential interfering substance. RESULTS: A total of 15,169 urine samples, from 7,803 patients, were tested for 3 years. Of the tested samples, 22 (0.15%) were positive by DRI Ecstasy Assay. None of them were positive by GC/MS. A cross-reactivity of fenofibrate's metabolite with MDMA using this assay was systematically found. CONCLUSION: Fenofibrate's interference with MDMA immunoassay was confirmed. Fenofibrate being widely prescribed, physicians had to be alerted that this treatment could lead to false-positive results.

Immunoglobulin D and cardiac amyloidosis: development and a case illustration.

Amyloidosis results from extra-cellular deposition of proteins which interfere with tissue function. We report the case of a patient with pathological heart involvement which is caused by immunoglobulin D amyloidosis, and review current data on the amyloidois diagnosis and management.

Working towards accreditation by the International Standards Organization 15189 Standard: how to validate an in-house developed method an example of lead determination in whole blood by electrothermal atomic absorption spectrometry.

Laboratories working towards accreditation by the International Standards Organization (ISO) 15189 standard are required to demonstrate the validity of their analytical methods. The different guidelines set by various accreditation organizations make it difficult to provide objective evidence that an in-house method is fit for the intended purpose. Besides, the required performance characteristics tests and acceptance criteria are not always detailed. The laboratory must choose the most suitable validation protocol and set the acceptance criteria. Therefore, we propose a validation protocol to evaluate the performance of an in-house method. As an example, we validated the process for the detection and quantification of lead in whole blood by electrothermal absorption spectrometry. The fundamental parameters tested were, selectivity, calibration model, precision, accuracy (and uncertainty of measurement), contamination, stability of the sample, reference interval, and analytical interference. We have developed a protocol that has been applied successfully to quantify lead in whole blood by electrothermal atomic absorption spectrometry (ETAAS). In particular, our method is selective, linear, accurate, and precise, making it suitable for use in routine diagnostics.

[Cooperations between biology laboratories of the establishments of healthcare]. / Coopérations entre laboratoires de biologie médicale des établissements de santé

In France, the cooperations between biological laboratories of the healthcare establishments increased after those realized in the private laboratories. The biologists are confronted with various hypotheses of organization. They are often complex because they may preserve the quality of the care and their continuity while realizing financial economies. These economies are mostly based on the global reduction in the staff and in the equipments by mutualising the biological tests with varying degrees. We describe the various elements to be taken into account (staff, activities, budget, quality, transport, materials) and propose many scenarios of cooperations, from a unique central shape to the transfer of very specialized tests, with their advantages and their inconveniences. The management of human aspects in these cooperations is determining to facilitate their success as well as a reliable preliminary inventory of fixtures.

[Heterophilic antibodies: be carefull!]. / Anticorps hétérophiles: restez vigilants !

The determination of plasma level of cardiac troponin I or T is recommended by the French Health Authority to diagnose myocardial infarction. However false positive results associated with the presence of heterophilic antibodies are described in the literature. This interference can lead to unnecessary invasive procedures, sometimes even dangerous. We report the case of a patient with falsely elevated troponin Ic concentration due to these antibodies. This case is characterized by the intensity of the abnormalities, the diversity of biological parameters affected and the discrepancies between biology and clinic. This case report confirms that modern immunoassays are always affected by heterophilic antibodies. We present here an example of such interference.

[Systemic amyloidosis revealed by an intense nephrotic syndrome]. / À propos d'une amylose révélée par un syndrome néphrotique intense.

We report the case of a patient with steroid-resistant nephrotic syndrome which is caused by a renal amyloidosis. This clinical case is characterized by intensity of clinicals and biologicals abnormalities and by its uncommun cause. We also review current data on the nephrotic syndrome as well as on the systemic amyloidosis and to evoke the indications of the immunoglobulin free-light-chains quantification in the diagnostic approach.

[Validation of plasma creatinine measurement on UniCel DxC 600 according to LAB GTA 04 recommendation]. / Vérification initiale d'une nouvelle méthode de dosage de la créatinine plasmatique sur UniCel (R) DxC 600 selon les recommandations du LAB GTA 04.

The accreditation process, according to NF EN ISO 15189, implies a prior evaluation of the new reagent on-site for the implementation of each new assay technique. Thus, our new standardized method for determination of creatinine (non compensated method) in plasma or serum on UniCel DxC 600 (Beckman Coulter) has been tested according to LAB GTA 04 protocol. The reagent meets the quality criteria recommended by Valtec protocol, except fidelity with the low concentration standard (50 micromol/L). Besides there is no problem of results transferability with the two other techniques used in the laboratory (Jaffe compensated and enzymatic methods performed on Cobas Integra 800).

Treatment of sonographically stratified multiloculated thoracic empyema by medical thoracoscopy.

INTRODUCTION: In cases of empyema, some form of intervention, either chest tube drainage, thoracoscopy, video-assisted thoracic surgery (VATS), or thoracotomy, with or without pleural fibrinolysis, is required. What the best approach is and when and how to intervene is a matter of debate. STUDY OBJECTIVE: To analyze the safety and outcome of medical thoracoscopy in the treatment of multiloculated empyema. METHODS: We report a retrospective series of 127 patients with thoracic empyema treated with medical thoracoscopy from 1989 to 2003 in three hospitals in Switzerland and Italy. All patients had multiloculated empyema as identified by chest ultrasonography. In the absence of multiloculation, or in case of fibrothorax, simple chest tube drainage or surgical VATS/thoracotomy were performed, respectively. RESULTS: Mean age +/- SD was 58 +/- 18 years (range, 9 to 93 years). In 47%, a microbiological diagnosis was made. Complications occurred in 9% of patients (subcutaneous emphysema, n = 3; air leak of 3 to 7 days, n = 9). No mortality was observed. Forty-nine percent of patients received postinterventional intrapleural fibrinolysis. Medical thoracoscopy was primarily successful in 91% of cases. In four patients, the insertion of an additional chest tube or a second medical thoracoscopy was required. Finally, 94% of patients were cured by nonsurgical means. Six percent of patients required surgical pleurectomy, mostly through thoracotomy. CONCLUSION: Multiloculated empyema as stratified by ultrasonography can safely and successfully be treated by medical thoracoscopy.