Perception of PrEP-related stigma in PrEP users: Results from the ANRS-PREVENIR cohort

INTRODUCTION

Since the advent of HIV pre-exposure prophylaxis (PrEP), stigma has been shown to be a major barrier to its uptake and adherence. It is therefore essential to define the proportion of users who consider that PrEP can negatively impact their image and the factors associated with this perception.

METHOD

We performed a multivariable logistic regression on data from the 2567 participants in the ANRS-PREVENIR study who answered the outcome question.

RESULTS

Almost one-third of the sample (comprising mostly cisgender men who have sex with men [94.3%]) considered that taking PrEP could give others a negative image of them. Younger participants (adjusted odds ratio [aOR] 0.98; 95% confidence interval [CI] 0.97-0.99) and more psychologically vulnerable participants (i.e., lower self-esteem score [aOR 0.98; 95% CI 0.96-0.99] and higher depression score [aOR 1.02; 95% CI 1.00-1.03]) were also more likely to have this perception. In contrast, participants encouraged to take PrEP by their main partner (aOR 0.67; 95% CI 0.51-0.88) and friends (aOR 0.79; 95% CI 0.66-0.95), and those who protected themselves more because they had knowledge of their most recent sexual partner's HIV status (aOR 0.83; 95% CI 0.69-0.99) and systematic use of PrEP and/or condoms during intercourse in the previous 3 months (aOR 0.80; 95% CI 0.67-0.96) were less likely to have this perception.

DISCUSSION

Given the strong interrelation between stigmatization (real or perceived), risky behaviours and adherence, our results emphasize the need for HIV prevention campaigns to promote a positive image of PrEP users. They also show that stigmatization and its effects need to be fully considered to improve HIV prevention offers to current and potential PrEP users who are most likely to be psychologically vulnerable.

Prosthesis-patient mismatch is an independent predictor of congestive heart failure after transcatheter aortic valve replacement

BACKGROUND

Little is known about the effect of prosthesis-patient mismatch (PPM) on outcomes after transcatheter aortic valve replacement. We reported previously an increased risk of PPM with the SAPIEN 3 transcatheter heart valve (S3-THV).

AIMS

To investigate the association of PPM with 1-year outcomes in patients with severe aortic stenosis (AS) implanted with S3-THV.

METHODS

Moderate PPM was defined by an indexed effective orifice area (iEOA)≤0.85cm²/m², and severe PPM by an iEOA<0.65cm²/m². Inclusion criteria were severe symptomatic AS and implantation with S3-THV. The primary endpoint was hospitalization for congestive heart failure (CHF) at 1 year; the secondary endpoint was all-cause mortality.

RESULTS

A total of 208 consecutive patients were included between 2016 and 2018. Male sex was prevalent (53.8%), mean age was 81.9±6.2 years, mean EuroSCORE II was 4.35±3.37, mean LVEF was 57.9±13%. Moderate and severe PPM were observed in 69 (33.2%) and 10 (4.8%) patients. Patients with PPM were younger (80.4±7 vs 82.8±5.41 years; P=0.006), had a larger BSA (1.84±0.19 vs 1.77±0.19 m²; P=0.01), a lower iEOA (0.73±0.08 vs 1.11±0.22 cm²/m²; P<0.001) and a higher mean gradient (14±4.6 vs 11.9±3.9mmHg; P<0.001). CHF occurred in 16.5% vs 7% (P=0.03). By multivariable analysis, PPM was independently associated with CHF (hazard ratio [HR] 3.17, 95% confidence interval [CI] 1.17 to 8.55; P=0.032), especially in patients with mitral regurgitation≥2/4 (HR>100, 95%CI>100 to>1000; P<0.01). PPM did not correlate with all-cause mortality (HR 0.90, 95%CI 0.22 to 3.03; P=0.86).

CONCLUSIONS

PPM after S3-THV implantation is strongly associated with CHF at 1 year, but is not correlated with overall mortality.

Left-ventricular non-compaction-comparison between different techniques of quantification of trabeculations: Should the diagnostic thresholds be modified?

BACKGROUND

Diagnosis of left ventricular non-compaction (LVNC) is challenging, and different imaging techniques propose different criteria.

AIM

To compare the value of two-dimensional transthoracic echocardiography (2D-TTE) and cardiac magnetic resonance (CMR) criteria in diagnosing LVNC, and to test a new trabecular quantification method obtained by 2D-TTE, exploring its relationship with CMR non-compacted mass quantification.

METHODS

From a multicentre French study, we selected 48 patients with LVNC and 20 with dilated cardiomyopathy (DCM) who underwent 2D-TTE and CMR. Current 2D-TTE (Jenni et al.) and CMR criteria (Petersen et al., Jacquier et al.), were tested. A new 2D-TTE method of trabecular quantification (percentage of trabecular area) was also proposed, and compared with current criteria.

RESULTS

The best cut-off values for the diagnosis of LVNC were a non-compacted/compacted ratio≥2.3 (Petersen et al.), a trabeculated left ventricular mass≥20% (Jacquier et al.) and a non-compacted/compacted ratio≥1.8 (Jenni et al.). Lowering the threshold for the criterion of Jenni et al. from>2 to ≥1.8 improved its sensitivity from 69% to 98%. The 2D-TTE percentage of trabecular area was 25.9±8% in the LVNC group vs. 9.9±4.4% in the DCM group (P<0.05), and was well correlated with CMR non-compacted mass (r=0.65; P<0.05). A 15.8% threshold value for 2D-TTE percentage of trabecular area predicted LVNC diagnosis with a specificity of 95% and a sensitivity of 92%; its sensitivity was better than that for the criteria of Jenni et al. (P<0.01) and Petersen et al. (P=0.03).

CONCLUSIONS

Revision of the current threshold for the criterion of Jenni et al. from>2 to ≥1.8 is necessary to improve LVNC diagnosis in patients with left ventricular dysfunction. A new 2D-TTE trabecular quantification method improves TTE diagnosis of LVNC.

Microgan electron cyclotron resonance ion source in a Van de Graaff accelerator terminal

The Van de Graaff accelerator at IRMM works since many years providing proton, deuteron, and helium beams for nuclear data measurements. The original ion source was of RF type with quartz bottle. This kind of source, as well known, needs regular maintenance for which the accelerator tank must be completely opened. The heavy usage at high currents of the IRMM accelerator necessitated an opening about once every month. In 2010, the full permanent magnet Microgan electron cyclotron resonance (ECR) ion source from PANTECHNIK was installed into a new terminal platform together with a solid state amplifier of 50 W, a dedicated dosing system for 4 gases (with respective gas bottles H(2), D(2), He, and Ar), and a set of dedicated power supplies and electronic devices for the remote tuning of the source. The new system shows a very stable behaviour of the produced beam allowing running the Van de Graaf without maintenance for several months. This contribution will describe the full installed system in details (working at high pressure in the terminal, spark effects, and optic of the extraction), as well as beam results in dc or pulsed mode.

Pantechnik new superconducting ion source: PantechniK Indian Superconducting Ion Source

The new ECR ion source PantechniK Indian Superconducting Ion Source (PKISIS) was recently commissioned at Pantechnik. Three superconducting coils generate the axial magnetic field configuration, while the radial magnetic field is done with the multi-layer permanent magnets. Special care was devoted to the design of the hexapolar structure, allowing a maximum magnetic field of 1.32 T at the wall of the 82 mm diameter plasma chamber. The three superconducting coils using low temperature superconducting wires are cooled by a single double stage cryo-cooler (4.2 K). Cryogen-free technology is used, providing reliability and easy maintenance at low cost. The maximum installed RF power (18.0 GHz) is of 2 kW. Metallic beams can be produced with an oven (T(max) = 1400 °C) installed with an angle of 5° with respect to the source axis or a sputtering system, mounted on the axis of the source. The beam extraction system is constituted of three electrodes in accel-decel configuration. The new source of Pantechnik is conceived for reaching optimum performances at 18 GHz RF frequencies. PKISIS magnetic fields are 2.1 T axial B(inj) and 1.32 T radial field in the wall, variable B(min) with an independent coil and a large and opened extraction region. Moreover, PKISIS integrates modern design concepts, like RF direct injection (2 kW availability), dc-bias moving disk, out-of-axis oven and axial sputtering facility for metal beams. Finally, PKISIS is also conceived in order to operate in a high-voltage platform with minor power consumption.

Multigan®: first experimental results

A new design of a multicharged ion source based on the MONO1000 ECRIS has been presented at the last ECR ion source (ECRIS) Workshop 2010. [L. Maunoury et al., in Proceedings of the XIXth International Workshop on ECR Ion Sources, Grenoble, France, 23-26 August 2010] This source has not only two opening at both ends but also a large space in the middle of the source enabling a direct contact with the ECR plasma. The source has been assembled mechanically and put on a test bench at the Pantechnik company. The primary tests have shown that the plasma ignition occurred at low pressure (10(-6) mbar) and low RF power (10 W). The first experimental results (<Q> = 1.30 for Ar and 1.85 for Xe) demonstrated the potential of this ion source in production of multicharged ion beams.

Development of a 1+/N+ setup for the production of multicharged radioactive alkali ions in SPIRAL

In the framework of the production of radioactive ion beams by the isotope separator online method, a new system has been developed at GANIL/SPIRAL I to produce multicharged alkali ions. The principle, referred to as the "direct 1+/N+ method," consists of a surface ionization source associated with a multicharged electron-cyclotron-resonance ion source without an intermediate mass separator. This new system has been tested online using a (48)Ca primary beam at 60.3 A MeV. The experimental evidence of the direct 1+/N+ process has been obtained for a potential difference between the two sources of 11 V and with a 1+/N+ charge breeding efficiency of 0.04% for (47)K(5+). This value is significantly lower than the value of 6% obtained for stable K ions with the standard 1+/N+ method. A possible explanation is given in the text.

The radioactive ion beam production systems for the SPIRAL2 project

The SPIRAL2 project, currently under construction at GANIL, will include an isotope separator on line based facility for the production and acceleration of radioactive ion beams. A superconducting linear accelerator will accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. These primary beams will be used to bombard both thick and thin targets. We are investigating three different techniques to produce the radioactive ion beams: (1) the neutron induced fission of uranium carbide, (2) the direct interaction of deuterons in a uranium carbide target, and (3) the interaction of a heavy ion beam with a target. All these production systems will be coupled to an ion source. Four kinds of ion sources are foreseen for the ionization of the radioactive atoms: an electron cyclotron resonance ion source, a surface ionization ion source, a forced electron beam induced arc discharge ion source, and a laser ion source depending on the characteristics of the desired radioactive ion beam in terms of intensity, efficiency, purity, etc. A presentation of the SPIRAL2 project and of the different production systems is given.

Status report of stable and radioactive ion beam production at GANIL

GANIL has been producing many stable and radioactive ion beams for nearly 25 years. Constant progresses have been made in terms of intensity, stability, and reliability. The intensity for some stable metallic beams now exceeds or approaches the p microA level at an energy up to 95 MeV/u, e.g., 1.14 p microA for (36)S (65% enriched) at 77 MeV/u, 0.35 p microA for (58)Ni (63% enriched) at 74 MeV/u. Some recent results with Magnesocene using the metallic ions from volatile compounds method should also make possible the production of metallic beams with an intensity greater than 1 p microA. This has still to be measured. The ISOL facility SPIRAL I has been in operation for almost six years. Up to now, 17 exotic He experiments have been done with 14 target/ion-source (TIS) units; 19 other experiments (with O, Ne, Ar, and Kr) have been achieved with 14 TISs. Statistics show a fairly good ratio of available beam time to scheduled beam time. The radioactive beams and available intensities are compiled in this report. Future developments on radioactive ion beam production are briefly presented, while more details will be discussed elsewhere at this conference.

Nuclear charge radius of 8He

The root-mean-square (rms) nuclear charge radius of 8He, the most neutron-rich of all particle-stable nuclei, has been determined for the first time to be 1.93(3) fm. In addition, the rms charge radius of 6He was measured to be 2.068(11) fm, in excellent agreement with a previous result. The significant reduction in charge radius from 6He to 8He is an indication of the change in the correlations of the excess neutrons and is consistent with the 8He neutron halo structure. The experiment was based on laser spectroscopy of individual helium atoms cooled and confined in a magneto-optical trap. Charge radii were extracted from the measured isotope shifts with the help of precision atomic theory calculations.

Maedi-visna virus, a model for in vitro testing of potential anti-HIV drugs

A series of beta-D- and beta-L-cytidine analogues were evaluated for their inhibitory effect on the replication of maedi-visna virus (MVV) strains KV1772 and MV1514 cultured on sheep choroid plexus cells and the sheep chondrocyte cell line G81092, respectively. Eleven cytidine analogues were selected for the anti-viral test. Five of them belong to the family of the 2',3'-dideoxycytidine analogues, well known for their activity against human immunodeficiency virus (HIV). The others, all newly synthesized, were potential anti-viral and/or anti-leukemic agents. None of the compounds under study had a toxic effect in both anti-viral assay systems up to a 300 microM concentration. Based on the cytopathic effects (CPE), the virus replication was completely inhibited by the five 2',3'-dideoxycytidine analogues at a concentration of 50 microM, whereas the others six newly synthesized compounds induced titre reductions of 4-5 log units. The effective concentration causing 50% reduction of CPE (EC50) was of 5 microM for the five 2',3'-dideooxycytidine analogues and for beta-L-XyloFc, whereas the value of 50 microM was found for the b-L-XyloC and the four 5-azacytidine compounds tested. All these data reveal a good correlation between inhibition of MVV replication by several nucleoside cytidine analogues and their reported anti-HIV activity.

Unnatural enantiomers of 5-azacytidine analogues: syntheses and enzymatic properties

2'-Deoxy-beta-L-5-azacytidine(L-Decitabine), beta-L-5-azacytidine, and derivatives were stereospecifically prepared starting from L-ribose or L-xylose. D- and L-enantiomers of 2'-deoxy-beta-5-azacytidine were weak substrates of human recombinant deoxycytidine kinase (dCK), whereas both enantiomers of beta-5-azacytidine or the L-xylo-analogues were not substrates of the enzyme. None of the reported derivatives of beta-L-5-azacytidine was a substrate of human recombinant cytidine deaminase (CDA).

Unnatural enantiomers of 5-azacytidine analogues: syntheses and enzymatic properties

Although 2'-deoxy-beta-D-5-azacytidine (Decitabine) and beta-D-5-azacytidine display potent antileukemic properties, their therapeutic use is hampered by their sensitivity to nucleophiles and to deamination catalysed by cytidine deaminase. As shown earlier [Shafiee M., Griffon J.-F., Gosselin G., Cambi A., Vincenzetti S., Vita A., Erikson S., Imbach J.-L., Maury G., Biochem. Pharmacol. 56 (1998) 1237-1242], beta-L-enantiomers of cytidine derivatives are resistant to cytidine deaminase. We thus synthesized several 5-azacytosine beta-L-nucleoside analogues to evaluate their enzymatic and biological properties. 2'-Deoxy-beta-L-5-azacytidine (L-Decitabine), beta-L-5-azacytidine, 1-(beta-L-xylo-furanosyl)5-azacytosine, and 1-(2-deoxy-beta-L-threo-pentofuranosyl)5-azacytosine were stereospecifically prepared starting from L-ribose and L-xylose. D- and L-enantiomers of 2'-deoxy-beta-5-azacytidine were weak substrates of human recombinant deoxycytidine kinase (dCK) compared to beta-D-deoxycytidine, whereas both enantiomers of beta-5-azacytidine or the L-xylo-analogues were not substrates of the enzyme. As expected, none of the presently reported derivatives of beta-L-5-azacytidine was a substrate of human recombinant cytidine deaminase (CDA). The prepared compounds were tested for their activity against HIV and HBV and they did not show any significant activity or cytotoxicity. In the case of L-Decitabine, this suggests that the enantioselectivities of concerned enzymes other than dCK and CDA might not be favourable.

Possible role of two phenylalanine residues in the active site of human cytidine deaminase

Site-directed mutagenesis on human cytidine deaminase (CDA) was employed to mutate specifically two highly conserved phenylalanine residues, F36 and F137, to tryptophan; at the same time, the unique tryptophan residue present in the sequence at position 113 was mutated to phenylalanine. These double mutations were performed in order to have for each protein a single tryptophan signal for fluorescence studies relative to position 36 or 137. The mutant enzymes thus obtained, W113F, F36W/W113F and F137W/W113F, showed by circular dicroism and thermal stability an overall structure not greatly affected by the mutations. The titration of Trp residues by N-bromosuccinimide (NBS) suggested that residue W113 of the wild-type CDA and W36 of mutant F36W/W113F are buried in the tertiary structure of the enzyme, whereas the residue W137 of mutant F137W/W113F is located near the surface of the molecule. Kinetic experiments and equilibrium experiments with FZEB showed that the residue W113 seems not to be part of the active site of the enzyme whereas the Phe/Trp substitution in F36W/W113F and F137W/W113F mutant enzymes had a negative effect on substrate binding and catalysis, suggesting that F137 and F36 of the wild-type CDA are involved in a stabilizing interaction between ligand and enzyme.

Low enantioselectivities of human deoxycytidine kinase and human deoxyguanosine kinase with respect to 2'-deoxyadenosine, 2'-deoxyguanosine and their analogs

The antiviral activity of L-nucleoside analogs depends in part on the enantioselectivity of nucleoside kinases which catalyse their monophosphorylation. The substrate properties of human recombinant deoxycytidine kinase (dCK) and human recombinant deoxyguanosine kinase (dGK) with respect to L-adenosine and L-guanosine analogs, in the presence of saturating amounts of ATP and relatively high concentrations of substrates, demonstrated a marked lack of enantioselectivity of both these enzymes. Human dCK catalysed the phosphorylation of D- and L-enantiomers of beta-dA, beta-araA, and beta-dG with enantioselectivities favoring the unnatural enantiomer for the adenosine derivatives and the natural enantiomer for 2'-deoxyguanosine. No other tested L-adenosine or L-guanosine analog was a substrate of dCK. Similarly, D- and L-enantiomers of beta-dA, beta-araA, and beta-dG were substrates of human dGK but with different enantioselectivities compared to dCK, especially concerning beta-dA. The present results indicate that human dCK and dGK have similar properties including substrate properties, relaxed enantioselectivities, and possibly catalytic cycles.

Derivatives of L-adenosine and L-guanosine as substrates for human deoxycytidine kinase

A series of analogues of L-adenosine and of L-guanosine, including beta-L-dA, beta-L-Ado, beta-L-araA, and beta-L-dG, have been shown to be substrates of human deoxycytidine kinase thus demonstrating the complete lack of enantioselectivity of this enzyme.