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The extent of the SARS-CoV-2 circulation and the COVID-19 epidemic in Tunisia three months after virus circulation was unknown. The aim of this study was to determine the extent of SARS-CoV-2 infection among household contacts of confirmed COVID-19 cases living in Hot spot areas of Great Tunis, Tunisia by estimating the seroprevalence of antibodies anti SARS-CoV-2 and to identify factors associated to seroprevalence at the first stage of the pandemic in order to guide decision making and to constitute a baseline for further longitudinal analysis of protective immunity to SARS-CoV-2. The National Observatory of New and Emerging Diseases (ONMNE), Ministry of Health Tunisia (MoH), with the support of the Office of the World Health Organization Representative in Tunisia and the WHO Regional Office for the Eastern Mediterranean (EMRO)), conducted a household cross-sectional survey on April 2020 in Great Tunis (Tunis, Ariana, Manouba and Ben Arous). The study was based on the WHO seroepidemiological investigation protocol for SARS-CoV-2 infection. SARS-CoV-2 specific antibodies (IgG and IgM) were qualitatively detected using a lateral immunoassay that detect SARS-CoV-2 nucleocapsid protein and administered by the interviewers. The included subjects were confirmed COVID-19 cases and their households contacts resided in hot spot areas (cumulative incidence rate ≥ 10 cases/100,000 inhabitants) of Great Tunis. Results: In total, 1165 subjects were enrolled: 116 confirmed COVID-19 cases (43 active cases and 73 convalescents cases) and 1049 household contacts resided in 291 households. The median age of participants was 39.0 with 31 years’ interquartile range (Min = 8 months; Max = 96 years). The sex ratio (M/F) was 0.98. Twenty-nine per cent of participants resided in Tunis. The global crude seroprevalence among household contacts was 2.5% (26/1049); 95% CI 1.6–3.6%, 4.8%; 95% CI 2.3–8.7% in Ariana governorate and 0.3%; 95% CI 0.01%–1.8% in Manouba governorate. In multivariate analysis, the associated factors independently related to seroprevalence were age ≥25 years (aOR = 5.1; 95% CI 1.2–22.0), history of travel outside Tunisia since January 2020 (aOR = 4.6; 95% CI 1.7–12.9), symptomatic illness in the previous four months (aOR = 3.5; 95% CI 1.4–9.0) and governorate of residence (p = 0.02). The low seroprevalence estimated among household contacts in Great Tunis reflect the effect of public health measures early taken (national lockdown, borders closed, remote work), the respect of non-pharmaceutical interventions and the efficacy of COVID-19 contact-tracing and case management at the first stage of the pandemic in Tunisia.

Background Immunotherapy targeting GD2 is very effective against high-risk neuroblastoma, though administration of anti-GD2 antibodies induces severe and dose-limiting neuropathic pain by binding GD2-expressing sensory neurons. Previously, the IgG1 ch14.18 (dinutuximab) antibody was reformatted into the IgA1 isotype, which abolishes neuropathic pain and induces efficient neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC) via activation of the Fc alpha receptor (FcαRI/CD89).Methods To generate an antibody suitable for clinical application, we engineered an IgA molecule (named IgA3.0 ch14.18) with increased stability, mutated glycosylation sites and substituted free (reactive) cysteines. The following mutations were introduced: N45.2G and P124R (CH1 domain), C92S, N120T, I121L and T122S (CH2 domain) and a deletion of the tail piece P131-Y148 (CH3 domain). IgA3.0 ch14.18 was evaluated in binding assays and in ADCC and antibody-dependent cellular phagocytosis (ADCP) assays with human, neuroblastoma patient and non-human primate effector cells. We performed mass spectrometry analysis of N-glycans and evaluated the impact of altered glycosylation in IgA3.0 ch14.18 on antibody half-life by performing pharmacokinetic (PK) studies in mice injected intravenously with 5 mg/kg antibody solution. A dose escalation study was performed to determine in vivo efficacy of IgA3.0 ch14.18 in an intraperitoneal mouse model using 9464D-GD2 neuroblastoma cells as well as in a subcutaneous human xenograft model using IMR32 neuroblastoma cells. Binding assays and PK studies were compared with one-way analysis of variance (ANOVA), ADCC and ADCP assays and in vivo tumor outgrowth with two-way ANOVA followed by Tukey’s post-hoc test.Results ADCC and ADCP assays showed that particularly neutrophils and macrophages from healthy donors, non-human primates and patients with neuroblastoma are able to kill neuroblastoma tumor cells efficiently with IgA3.0 ch14.18. IgA3.0 ch14.18 contains a more favorable glycosylation pattern, corresponding to an increased antibody half-life in mice compared with IgA1 and IgA2. Furthermore, IgA3.0 ch14.18 penetrates neuroblastoma tumors in vivo and halts tumor outgrowth in both 9464D-GD2 and IMR32 long-term tumor models.Conclusions IgA3.0 ch14.18 is a promising new therapy for neuroblastoma, showing (1) increased half-life compared to natural IgA antibodies, (2) increased protein stability enabling effortless production and purification, (3) potent CD89-mediated tumor killing in vitro by healthy subjects and patients with neuroblastoma and (4) antitumor efficacy in long-term mouse neuroblastoma models.

Backgroundwhile the duration of dual antiplatelet therapy (DAPT) following coronary angioplasty for chronic coronary syndrome (CCS) recommended by the European Society of Cardiology has decreased over the last decade, little is known about the adherence to those guidelines in clinical practice in France.AimTo analyze the real duration of DAPT post coronary angioplasty in CCS, as well as the factors affecting this duration.MethodsBetween 2014 and 2019, 8.836 percutaneous coronary interventions for CCS from the France-PCI registry were evaluated, with 1 year follow up, after exclusion of patients receiving oral anticoagulants, procedures performed within one year of an acute coronary syndrome, and repeat angioplasty.ResultsPost-percutaneous coronary intervention (PCI) DAPT duration was > 12 months for 53.1% of patients treated for CCS; 30.5% had a DAPT between 7 and 12 months, and 16.4% a DAPT ≤ 6 months. Patients with L-DAPT (>12 months) were at higher ischemic risk [25.0% of DAPT score ≥2 vs. 18.8% DAPT score ≥2 in S&I-DAPT group (≤12 months)]. The most commonly used P2Y12 inhibitor was clopidogrel (82.2%). The prescription of ticagrelor increased over the period.Conclusionspost-PCI DAPT duration in CCS was higher than international recommendations in the France PCI registry between 2014 and 2019. More than half of the angioplasty performed for CCS are followed by a DAPT > 12 months. Ischemic risk assessment influences the duration of DAPT. This risk is probably overestimated nowadays, leading to a prolongation of DAPT beyond the recommended durations, thus increasing the bleeding risk.

Background: Coronavirus disease 2019 (COVID-19) has spread rapidly across the world. Tunisia reacted early to COVID-19, resulting in a low number of infections during the first wave of the pandemic. This study was performed to model the effects of different interventions on the evolution of cases and to compare these with the Tunisian experience. Methods: A stochastic transmission model was used to quantify the reduction in number of cases of COVID-19 with the interventions of contact tracing, compliance with isolation, and a general lockdown. Results: In the model, increasing contact tracing from 20% to 80% after the first 100 cases reduced the cumulative number of infections (CNI) by 52% in 1 month. Similarly, increased compliance with isolation from 20% to 80% after the first 100 cases reduced the CNI by 45%. These reductions were smaller if the interventions were implemented after 1000 cases. A general lockdown reduced the CNI by 97% after the first 100 cases. Tunisia implemented its general lockdown after 75 cases were confirmed, which reduced the cumulative number of infected cases by 86% among the general population. Conclusions: This study shows that the early application of critical interventions contributes significantly to reducing infections and the evolution of COVID-19 in a country. Tunisia’s early success with the control of COVID-19 is explained by its quick response.

Coronary artery calcification is a complex process found predominantly in the elderly population. Coronary angiography frequently lacks sensitivity to detect, evaluate and quantify these lesions. Yet calcified lesions are considered stable, it remains associated with a higher rate of peri procedural complications during percutaneous coronary intervention (PCI) including an increased risk of stent under expansion and struts mal apposition leading to poor clinical outcome. Intracoronary imaging (Intravascular Ultra Sound (IVUS) and Optical Coherence Tomography (OCT)) allows better calcified lesions identification, localization within the coronary artery wall (superficial or deep calcifications), quantification. This lesions characterization allows a better choice of dedicated plaque-preparation tools (modified balloons, rotational or orbital atherectomy, intravascular lithotripsy) that are crucial to achieve optimal PCI results. OCT could also assess the impact of these tools on the calcified plaque morphology (plaque fracture, burring effects…). An OCT-guided tailored PCI strategy for calcified lesions still requires validation by clinical studies which are currently underway.

The impact that post-dilatation has on the risk of experiencing conduction disorders after post-transcatheter aortic valve replacement with self-expanding valves (SE-TAVR) is unclear. We compared the rate of developing an atrioventricular (AV) high-grade conduction disorder and permanent pacemaker implantation (PPI) in post-TAVR patients undergoing post-dilatation. We enrolled patients with severe symptomatic calcified aortic stenosis (CAS) who were undergoing SE-TAVR between 1 January 2016, and 19 April 2019 at a single French center. Of the 532 patients treated with SE-TAVR, 417 subjects (78.4%) received Corevalve Evolute R and 115 subjects (21.6%) received the latest-generation Corevalve Evolute Pro valve. In total, 104/532 patients (19.5%; 21.6% with Evolute R vs. 12.2% with Evolute Pro, p = 0.024) required post-dilatation. Evolut R was associated with an increased risk of post-dilatation (odds ratio 2.1 (1.01–4.33, p = 0.046)). We did not observe any post-dilatation increases in AV or in intra- and interventricular conduction disorders. In total, 26.1% of participants needed PPI within the first 30 post-procedure days (p = 0.449). Post-dilatation was not associated with a higher PPI risk (subdistribution hazard ratio 1.033 (0.726–1.471); p = 0.857). No significant differences existed between the groups in terms of one-year mortality (10.3%; p = 0.507). Post-dilatation in SE-TAVR did not increase the rate of electrical conduction disorders and PPI in the early implantation phase. The latest generation of SE-TAVR valves was associated with less need for post-dilatation.

[Display omitted] Transcatheter aortic valve implantation is unfeasible for 10–15% of patients using the conventional transfemoral approach. Other alternative approaches, such as the subclavian approach, have emerged, with no clear recommendation indicating the superiority of one technique over another. To compare the 1-month mortality and postprocedural outcomes of patients undergoing transcatheter aortic valve implantation using a self-expandable valve via transfemoral and subclavian access. This was a retrospective single-centre study including 1496 patients who underwent transcatheter aortic valve implantation between January 2016 and December 2020 at Clermont-Ferrand University Hospital, France. Propensity score matching was used to compare transfemoral and subclavian access. After building two propensity score-matched groups of 221 patients each with either access route (total n = 442), baseline characteristics were similar. The procedure duration was significantly longer in the subclavian access group (53 [45–64] versus 60 [51–72] minutes; P < 0.001), but with a lower amount of contrast agent (138 [118–165] versus 123 [105–150] mL; P < 0.001), fluoroscopy time (11.2 [9–14] versus 9.9 [7–12] minutes; P < 0.001) and radiation dose (397 [264–620] versus 321 [217–485] mGy; P < 0.001). No significant difference was observed concerning 1-month mortality (odds ratio 1.62, 95% confidence interval 0.52–5.03; P = 0.39) or periprocedural complications. Follow-up at 1 year confirmed no difference in longer-term mortality (hazard ratio 0.78, 95% confidence interval 0.52–5.03; P = 0.43). The subclavian approach provides similar results to the transfemoral approach in terms of mortality, efficacy and safety; it is a reasonable and effective alternative when the reference transfemoral approach is impossible or seems complex. [ABSTRACT FROM AUTHOR]

Neovascular age-related macular degeneration (nvAMD) is characterized by choroidal blood vessels growing into the subretinal space, leading to retinal pigment epithelial (RPE) cell degeneration and vision loss. Vessel growth results from an imbalance of pro-angiogenic (e.g., vascular endothelial growth factor [VEGF]) and anti-angiogenic factors (e.g., pigment epithelium-derived factor [PEDF]). Current treatment using intravitreal injections of anti-VEGF antibodies improves vision in about 30% of patients but may be accompanied by side effects and non-compliance. To avoid the difficulties posed by frequent intravitreal injections, we have proposed the transplantation of pigment epithelial cells modified to overexpress human PEDF. Stable transgene integration and expression is ensured by the hyperactive Sleeping Beauty transposon system delivered by pFAR4 miniplasmids, which have a backbone free of antibiotic resistance markers. We demonstrated efficient expression of the PEDF gene and an optimized PEDF cDNA sequence in as few as 5 × 103 primary cells. At 3 weeks post-transfection, PEDF secretion was significantly elevated and long-term follow-up indicated a more stable secretion by cells transfected with the optimized PEDF transgene. Analysis of transgene insertion sites in human RPE cells showed an almost random genomic distribution. The results represent an important contribution toward a clinical trial aiming at a non-viral gene therapy of nvAMD. Keywords: neovascular age-related macular degeneration, non-viral ex vivo gene therapy, sleeping beauty transposon system, pFAR4 miniplasmids, primary pigment epithelial cells, pigment epithelium-derived factor

Single-step orthogonal chemical functionalization procedures have been developed with patterned gold on silica surfaces. Different combinations of a silane and a thiol were simultaneously deposited on a gold/silica heterogeneous substrate. The orthogonality of the functionalization (i.e., selective grafting of the thiol on the gold areas and the silane on the silica) was demonstrated by X-ray photoelectron spectroscopy (XPS) as well as time-of-flight secondary ion mass spectrometry (ToF–SIMS) mapping. The orthogonal functionalization was used to immobilize proteins onto gold nanostructures on a silica substrate, as demonstrated by atomic force microscopy (AFM). These results are especially promising in the development of future biosensors where the selective anchoring of target molecules onto nanostructured transducers (e.g., nanoplasmonic biosensors) is a major challenge.

New-onset left bundle branch block (LBBB) is one of the most frequent complications after transcatheter aortic valve implantation (TAVI) and is associated with delayed high degree atrioventricular (AV) block. The objectives of this study were to determine the incidence of AV block in such a population and to assess the performance and safety of a risk stratification algorithm on the basis of electrophysiology study (EPS) followed by implantation of a pacemaker or implantable loop recorder (ILR). This was a prospective open-label study with 12-month follow-up. From June 8, 2015, to November 8, 2018, 183 TAVI recipients (mean age 82.3 ± 5.9 years) were included at 10 centers. New-onset LBBB after TAVI persisting for >24 hours was assessed by electrophysiology study during initial hospitalization. High-risk patients (His-ventricle interval ≥70 ms) were implanted with a dual-chamber pacemaker recording AV conduction disturbance episodes. Patients at lower risk were implanted with an ILR with automatic remote monitoring. A high-grade AV conduction disorder was identified in 56 patients (30.6%) at 12 months. Four subjects were symptomatic, all in the ILR group. No complications were associated with the stratification procedure. Patients with His-ventricle interval ≥70 ms displayed more high-grade AV conduction disorders (53.2% [25 of 47] vs 22.8% [31 of 136]; P <.001). In a multivariate analysis, His-ventricle interval ≥70 ms was independently associated with the occurrence of a high-grade conduction disorder (subdistribution hazard ratio 2.4; 95% confidence interval 1.2–4.8; P =.010). New-onset LBBB after TAVI was associated with high rates of high-grade AV conduction disturbances. The stratification algorithm provided safe and valuable aid to management decisions and reliable guidance on pacemaker implantation. [Display omitted] [ABSTRACT FROM AUTHOR]

The Gram negative bacterium Pseudomonas aeruginosa (PA) is an opportunistic bacterium that causes severe and chronic infection of immune-depressed patients. It has the ability to form a biofilm that gives a selective advantage to the bacteria with respect to antibiotherapy and host defenses. Herein, we have focused on the tetrameric soluble lectin which is involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. It binds to l-fucose, d-mannose and glycan exposing terminal fucose or mannose. Using a competitive assay on microarray, 156 oligosaccharides and polysaccharides issued from fermentation or from the biomass were screened toward their affinity to LecB. Next, the five best ligands (Lewisa, Lewisb, Lewisx, siayl-Lewisx and 3-fucosyllactose) were derivatized with a propargyl aglycon allowing the synthesis of 25 trivalent, 25 tetravalent and 5 monovalent constructions thanks to copper catalyzed azide alkyne cycloaddition. The 55 clusters were immobilized by DNA Directed immobilization leading to the fabrication of a glycocluster microarray. Their binding to LecB was studied. Multivalency improved the binding to LecB. The binding structure relationship of the clusters is mainly influenced by the carbohydrate residues. Molecular simulations indicated that the simultaneous contact of both binding sites of monomer A and D seems to be energetically possible.

Site-directed mutagenesis has greatly helped researchers both to understand the precise role of specific residues in coding sequences and to generate variants of proteins that have acquired new characteristics. Today's demands for more complete functional cartographies of proteins and advances in selection and screening technologies require that site-directed mutagenesis be adapted for high-throughput applications. We describe here the first generation of a library of single and multiple site-directed mutants using a mixture of oligonucleotides synthesized on DNA chips. We have used the human interleukin 15 (IL15) gene as a model, of which 37 codons were simultaneously targeted for substitution by any of eight possible codons. Ninety-six clones were sequenced, exhibiting a broad spectrum of targeted substitutions over the whole gene length with no unwanted mutations. Libraries produced using such pools of oligonucleotides open new perspectives to direct the evolution of proteins in vitro, by enabling the simple, rapid, and cost-effective generation of large tailor-made genetic diversities from any gene.

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BackgroundAntiretroviral Treatment (ART) significantly reduces HIV transmission. We conducted a cost-effectiveness analysis of the impact of expanded ART in South Africa.MethodsWe model a best case scenario of 90% annual HIV testing coverage in adults 15-49 years old and four ART eligibility scenarios: CD4 count ResultsExpanding ART to CD4 count ConclusionIncreasing the provision of ART to

Background. The rapid scale-up of antiretroviral therapy in resource-limited settings has greatly increased demand for antiretroviral medicines and raised the importance of good forward planning, especially in the context of the new 2010 WHO treatment guidelines. Methods. Forecasting of the number of people receiving antiretroviral therapy from 2010 to 2012 was produced using three approaches: linear projection, country-set targets, and a restricted scenario. Two additional scenarios were then used to project the demand for various antiretroviral medicines under a fast and slower phase-out of stavudine. Results. We projected that between 7.1 million and 8.4 million people would be receiving ART by the end of 2012. Of these, 6.6% will be on second-line therapy. High variation in forecast includes reductions in the demand for d4T and d4T increases in the demand for tenofovir, emtricitabine followed by efavirenz, ritonavir, zidovudine and lopinavir; lamivudine, atazanavir, and nevirapine. Conclusion. Despite the global economic crisis and in response to the revised treatment guidelines, our model forecasts an increasing and shifting demand for antiretrovirals in resource-limited settings not only to provide treatment to new patients, but also to those switching to less toxic regimens.

Retention of patients on antiretroviral therapy (ART) over time is a proxy for quality of care and an outcome indicator to monitor ART programs. Using existing databases (Antiretroviral in Lower Income Countries of the International Databases to Evaluate AIDS and Médecins Sans Frontières), we evaluated three sampling approaches to simplify the generation of outcome indicators.We used individual patient data from 27 ART sites and included 27,201 ART-naive adults (≥15 years) who initiated ART in 2005. For each site, we generated two outcome indicators at 12 months, retention on ART and proportion of patients lost to follow-up (LFU), first using all patient data and then within a smaller group of patients selected using three sampling methods (random, systematic and consecutive sampling). For each method and each site, 500 samples were generated, and the average result was compared with the unsampled value. The 95% sampling distribution (SD) was expressed as the 2.5(th) and 97.5(th) percentile values from the 500 samples. Overall, retention on ART was 76.5% (range 58.9-88.6) and the proportion of patients LFU, 13.5% (range 0.8-31.9). Estimates of retention from sampling (n = 5696) were 76.5% (SD 75.4-77.7) for random, 76.5% (75.3-77.5) for systematic and 76.0% (74.1-78.2) for the consecutive method. Estimates for the proportion of patients LFU were 13.5% (12.6-14.5), 13.5% (12.6-14.3) and 14.0% (12.5-15.5), respectively. With consecutive sampling, 50% of sites had SD within ±5% of the unsampled site value.Our results suggest that random, systematic or consecutive sampling methods are feasible for monitoring ART indicators at national level. However, sampling may not produce precise estimates in some sites.