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A new method for the detection by flow cytometry of anti-double-stranded DNA antibodies and of circulating immune complexes (IC) containing endogenous DNA (IC-eDNA) is described. From each serum sample, two samples were taken, one was used to detect IC-eDNA. The other to detect anti-DNA antibodies was incubated with calf thymus DNA. ICs were isolated by polyethylene glycol precipitation or by cryoprecipitation, after which immunoglobulins were labeled with FITC-conjugated anti-human globulin. Serum samples from 63 systemic lupus erythematosus (SLE) patients, 32 incomplete lupus, and 87 control patients were tested. Detection of anti-dsDNA antibodies by flow cytometry had a diagnostic sensitivity and specificity almost comparable to routine tests, the fluorescent enzyme immunoassay EliA™-dsDNA test, and the ultrasensitive Crithidia luciliae indirect immunofluorescence test. In 21 (33%) out of 63 SLE serum samples, IC-eDNA was detected. In these samples, free anti-dsDNA antibodies were hardly detectable or undetectable by flow cytometry or by routine tests. When anti-DNA antibodies are neutralized by endogenous DNA and can no longer be detected by routine tests, the serologic diagnosis and the follow-up of relapses in patients with SLE is compromised. To overcome this obstacle, we propose an accessible solution: the detection of circulating IC-eDNA by flow cytometry., Competing Interests: The authors have declared that no conflict of interest exists., (Copyright © 2019 Nisen Abuaf et al.)

The transition period between elementary and middle school is a high-risk period for smoking initiation. Hence the importance of primary prevention programs in adolescent populations. The development and implementation of appropriate preventive measures requires information on tobacco use among adolescents. The objective of this study was to estimate the prevalence of smoking among middle school students in Casablanca and to describe associated drug use. A cross-sectional study was conducted in 2010 in six collèges (middle schools) in Casablanca. The average age of the students was 16.3 years (SD = 2.1). 55% of the students were female. Overall smoking prevalence was 7.5% (CI 95% = 5.5% - 10.1%) ? 11.4% among boys and 4.6% among girls. 52.5% of the smokers began smoking between the ages of 14 and 18. The reasons for smoking included smoking as a way of escaping from problems (30%), relaxation (16%) and experience (7%). Smoking behavior was associated with drug use in 23.3% of smokers, compared to 0.6% among non-smokers (p < 10?3). These results suggest the need for prevention measures aimed at strengthening tobacco control policies in schools and other gathering places for young people.

Recombinant human annexin V was bound covalently to 9 nm maghemite (gamma Fe2O3) nanoparticles, yielding annexin-ferrofluid (AnxFF), and used to separate annexin-bound red blood cells (RBC) in a magnetic field and estimate their percentage in various bloods. Annexin binding in normal human RBC increased proportionately with storage from 8% on day 2 to 42% on day 100. Enhanced AnxFF binding was associated with various pathologies. Thus, normal blood contained 10.7 +/- 5.9% AnxFF binding RBC; bloods with normal sedimentation rates (albeit with some disease necessitating analysis) contained 23.5 +/- 6.2%; those with high sedimentation rates contained 51.5 +/- 12.3%; sickle cell anaemia patients' blood contained 50.0 +/- 9.3%, and bloods from patients with other pathologies (deforming rheumatic disease, cancer necessitating chemotherapy, etc.) contained 58.6 +/- 7.6% AnxFF binding RBC. Enhanced Ca+2-dependent annexin binding reflects a loss of the asymmetric distribution of anionic phospholipids in plasma membranes which may constitute a signal for the destruction of the modified cells by the reticuloendothelial system. Once these preliminary results are confirmed, the determination of the fraction of AnxFF bound erythrocytes, following their magnetic separation, could prove a simple and rapid quality test for example in the context of blood transfusion.