Physico-chemical characterization and in vitro inflammatory and oxidative potency of atmospheric particles collected in Dakar city's (Senegal).

Exposure to atmospheric pollutants has been recognized as a major risk factor of respiratory and cardiovascular diseases. Fine particles (PM2.5) and a coarser fraction (PM>2.5) sampled at an urban site in Dakar (HLM), characterized by high road traffic emissions, were compared with particles sampled at a rural area, Toubab Dialaw located about 40 km from Dakar. The physicochemical characteristics of samples revealed that PMs differ for their physical (surface area) and chemical properties (in terms of CHN, metals, ions, paraffins, VOCs and PAHs) that were 65-75% higher in urban samples. Moreover the fine PMs contain higher amounts of anthropogenic related pollutants than the PM>2.5 one. These differences are sustained by the ratios reported for the analysed PAHs which suggest as predominant primary emission sources vehicle exhausts at urban site and biomass combustion at the rural site. The inflammatory response and the oxidative damages were evaluated in BEAS-2B cells by the quantification of 4 selected inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-8) and of total carbonylated proteins and the oxidative DNA adduct 8-OHdG after 8 or 24 h exposure. In accordance with the different sources and different physical and chemical properties, the inflammatory response and the oxidative damages were found higher in bronchial cells exposed to urban PMs. These data confirm the importance, also for West African countries, to evaluate the correlation between PM physico-chemical properties and potential biological impacts.

Assessment of potentially preventable hospitalizations in the regional hospital of Saint-Louis, Senegal.

INTRODUCTION: The "potentially preventable hospitalizations (PPH)'' are hospital admissions that could have been avoided through effective primary care given at the appropriate time. Non-communicable diseases (NCDs), causes of PPH, are the leading cause of death worldwide with significant socioeconomic consequences especially in developing countries. This study aimed to assess the burden of potentially preventable hospitalizations in the St. Louis regional hospital. METHODS: This was a descriptive cross-sectional study. The surveyed population consisted of all patients older than one year, admitted to St. Louis hospital for more than four (04) hours time between January 20 and April 30, 2015. Patients hospitalized in surgery (general surgery, ENT, ophthalmology), maternity and neonatology, as well as those who refused or were unable to participate in the study were excluded. RESULTS: The study included one hundred forty four (144) individuals with an average age of 54.68±15 years (17-88 years) and sex ratio woman/man of 1.21. The PPH represented 54% of all hospitalizations. The main causes of hospitalizations were diabetes with 22.1%, chronic kidney disease 12%, hypertension 10.9%, Stroke 6.4% and finally broncho-pulmonary diseases 2.6%. The average length of stay was 6.68±5.51 days. The average distance between the residence and the hospital was 26.51±60KM with a median of 3.5KM. The average cost of care was Euros 104.583 ±83.51. For 61.10%, it was a first hospitalization and for 30.60%, a second one. The Knowledge about signs of disease severity had changed significantly at the end of hospitalization, from 29% at the beginning to 98% at the end of stay in hospital. As for the means of prevention, 30.55% reported knowing them before their hospitalization and 68% after hospitalization. CONCLUSION: Potentially preventable hospitalizations are a heavy burden for the population of St. Louis. Their negative social and economic impacts may hinder health policies initiated to relieve vulnerable groups. Their prevention should be a national priority.

HIV and Tuberculosis co-infection impacts T-cell activation markers but not the numbers subset of regulatory T-cells in HIV-1 infected patients.

BACKGROUND: Tuberculosis (TB) has been shown to accelerate the clinical course of HIV infection, but the mechanisms by which this occurs are not well understood. Regulatory T-cells (Tregs) are known to dampen hyperactivation of the immune cells, but it remains unclear whether hyperactivation of T-cells in HIV infection is associated with a decrease of Tregs and what the effect Mycobacterium tuberculosis (MTB) co-infection has on T-cell activation and Tregs. OBJECTIVES: In this study, we aim to evaluate whether active TB is associated with the increased expression of T-cell activation markers and reduced number of Treg cells in HIV-1-infected patients. METHODS: This study was conducted on 69 subjects consisting of 20 HIV-infected patients, 20 HIV and MTB co-infected patients, 19 MTB-infected patients and 10 uninfected control subjects negative for both MTB and HIV. The frequencies of T-cell activation markers (CD38 and HLA-DR) and Treg cells (CD4+CD25+CD127-) were measured by flow cytometry. RESULTS: Significantly higher expression of CD38 and HLA-DR on CD4+ and CD8+ T-cells was found in MTB and HIV co-infected patients compared with HIV-infected patients. However, no significant difference in the percentage of Treg cells was reported between HIV patients with TB and those without. The study also showed a negative correlation between regulatory T-cells frequency and CD4+ T-cell counts. CONCLUSION: These results suggest that TB enhances the expression of peripheral T-cell activation markers during HIV infection, whilst having no impact on the percentages of Treg cells.