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This cross sectional study was conducted in 2018 in Côte d'Ivoire to assess PrEP acceptability among men who have sex with men (MSM). Two hundred and one men were asked on their intention to use PrEP if made available. Logistic regression accounting for the sampling design was used to analyze associations between high PrEP acceptability and different independent variables including barriers and facilitators. Participants were mostly young (mean age = 25 years), educated (82% with secondary/postsecondary education) and single (95.5%). On average, 3.4 episodes of anal sex were reported monthly and 37.8% of men did not use a condom at last sex. Most MSM (72.6%) had heard of PrEP before enrollment. Overall, 35.3% reported that they would use PrEP very probably if made available. In multivariate analysis, factors associated with high PrEP acceptability were condom use at last sexual intercourse (Odds ratio (OR) = 2.51; 95%Confidence interval (95%CI) = 1.45-4.33); insertive sex as compared to versatile sex (OR = 2.56; 95%CI = 1.14-5.67); free PrEP delivery (OR = 2.45; 95%CI = 1.07-5.59), concerns about side effects (OR = 0.66; 95%CI = 0.48-0.90), and being preoccupied by the fact that post-PrEP antiretroviral therapy could be inefficient (OR = 0.25; 95%CI = 0.14-0.44). PrEP implementation among MSM in Côte d'Ivoire should be accompanied by awareness raising campaigns explaining its utility.

In Benin, consistent condom use among men who have sex with men (MSM)  is relatively low and providing them with Pre-exposure prophylaxis (PrEP) could be of great relevance. We aimed to describe PrEP knowledge and intention to use it; identify key facilitators and barriers to PrEP; and describe the perceived impact of PrEP on unsafe sexual behavior. MSM, 18 years or older, HIV-negative or of unknown status, were enrolled in five cities of Benin. Intention to use PrEP was assessed through five focus groups (FG). Data were analyzed using manual thematic sorting. Thirty MSM (six per city) participated in the FG. Mean age (standard deviation) was 27.1 (5.0) years. All participants expressed the intention to use PrEP if made available. Facilitators of PrEP use were: availability of medication, safety, absence of constraints as well as freedom to have multiple sex partners and sex with HIV-positive friends. Barriers were: complex procedures for obtaining medication, size and taste of medication, cost of medication, poor PrEP awareness.. Eighteen men admitted that PrEP could lead to decrease in or even abandonment of condom use. In conclusion, MSM showed openness to use PrEP if available, although they recognized that it could lead to risk compensation.

In cell culture studies, foetal calf serum (FCS) comprising numerous different proteins is added, which might coat the surface of engineered nanomaterials (ENMs) and thus could profoundly alter their biological activities. In this study, a panel of industrially most relevant metal oxide nanoparticles (NPs) was screened for toxic effects in A549 lung epithelial cells and RAW264.7 macrophages in the presence and absence of FCS. In medium without FCS amorphous SiO2-NPs were the most cytotoxic NPs and induced a significant pro-inflammatory response in both cell types. An increased anti-oxidative response after exposure to SiO2-NPs was, however, only observed in RAW264.7 macrophages. Furthermore, pre-coating of SiO2-NPs with FCS proteins or simply bovine serum albumin abrogated responses in A549 lung epithelial cells. Thus, the protein corona bound to the surface of SiO2-NPs suppresses their biological effects, an issue which needs to be more carefully considered for in vitro-in vivo extrapolations.

The use of nanostructured silica (SiO2) particles is no longer restricted to biomedical and (bio-) technological fields but rather finding applications in products of the food industry. Thus, our studies on the toxicological relevance of SiO2 nanoparticles focused on cytotoxic effects, the modulation of the cellular redox status and the impact on DNA integrity in human colon carcinoma cells (HT29). The results indicate that these SiO2 nanoparticles stimulate the proliferation of HT29 cells, depending on the incubation time and the particle size. The cytotoxicity of the investigated SiO2 nanoparticles was found to depend on the concentration, size and on the FCS content of the culture medium. Furthermore, SiO2 seem to interfere with glutathione biosynthesis. The results indicate further that effects of SiO2 NPs are not mediated by oxidative stress but by interference with the MAPK/ERK1/2 as well as the Nrf2/ARE signalling pathways. Additionally, investigations regarding DNA integrity revealed no substantial (oxidative) DNA damage.

From September 2008 to December 2011, we enrolled and followed-up 247 HIV-negative, 88 untreated and 32 treated HIV-positive female sex workers (FSWs), as well as 238 untreated and 115 treated HIV-positive patients from the general population (GP) of Cotonou, Benin. We wanted to assess the effect of antiretroviral therapy (ART) on sexual risk-taking in FSWs and patients from the GP. We used multivariate log binomial regression models for repeated measures to compare risky behaviours reported during pre-ART and post-ART visits and we performed linear time-trend analyses to assess changes in condom use in all five groups. At 58.8% of pre-ART and 45.3% of post-ART visits (adjusted p-value=0.293), treated FSWs have reported ≥16 clients during the last week of work. Inconsistent condom use with clients over the same period decreased by more than 50% (from 20.7 to 10.0%, adjusted p-value=0.082). In treated patients from the GP, inconsistent condom use with regular partners during the last four months was reported at 52.8% of pre-ART and 53.5% of post-ART visits (p=0.778). Reported casual sex was stable (36.8% versus 38.7%, adjusted p-value=0.924). In linear time-trend analyses, there was a significant downward trend in inconsistent condom use at the early stage of the study and stability thereafter in all HIV-negative and HIV-positive FSWs. There was no negative alteration in sexual behaviour following ART initiation either inpatients from the GP or in FSWs. The results underscore the key role of concomitant sexual risk-reduction strategies.

In this article, we review and analyze different modes of exposure to ultrafine particles in order to assess particle-induced inflammatory responses and the underlying mechanisms in vitro and in vivo. Based on results from monocytic cells cultured under submerged conditions, we discuss (1) the impact of particle properties such as surface area and oxidative potential on lipid metabolism as a highly sensitive regulatory pathway and (2) the interference of diesel exhaust particles with toll-like receptor-mediated inflammatory responses. Furthermore, new developments of air-liquid interface exposure used as an alternative approach to simulate cell particle interactions are presented. In addition to the in vitro approaches, animal exposure studies are described that apply selected mouse models to elucidate potential allergic and inflammatory pulmonary responses and mast-cell-related mechanisms after particle exposure. Long-term inhalation of ultrafine particles might lead to irreversible changes in lung structure and function. Clinical studies addressing the characteristics of inflammatory airway cells are a promising approach to understand underlying pathophysiological mechanisms in chronic obstructive pulmonary disease. Finally, a potential outcome of human particle exposure is chronic cough in children. Here, discrimination between asthmatic and nonasthmatic cough by means of immunological parameters appears to be an important step toward improving diagnosis and therapy.