Acrylamide (AA) is a suspected human carcinogen generated in carbohydrate-rich foodstuffs upon heating. Glycidamide (GA), formed via epoxidation, presumably mediated by cytochrome P450 2E1, is thought to be the active metabolite playing a central role in AA genotoxicity. In this work we investigated DNA damage induced by AA and GA in mammalian cells, using V79 Chinese hamster cells. For this purpose, we evaluated two cytogenetic end points, chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs), as well as the levels of specific GA-DNA adducts, namely, N7-(2-carbamoyl-2-hydroxyethyl)guanine (N7-GA-Gua) and N3-(2-carbamoyl-2-hydroxyethyl)adenine (N3-GA-Ade) using high-performance liquid chromatography coupled with tandem mass spectrometry. GA was more cytotoxic and clastogenic than AA. Both AA and GA induced CAs (breaks and gaps) and decreased the mitotic index. GA induced SCEs in a dose-responsive manner; with AA, SCEs were increased at only the highest dose tested (2mM). A linear dose-response relationship was observed between the GA concentration and the levels of N7-GA-Gua. This adduct was detected for concentrations as low as 1 microM GA. N3-GA-Ade was also detected, but only at very high GA concentrations (>or= 250 microM). There was a very strong correlation between the levels of N7-GA-Gua in the GA- and AA-treated cells and the extent of SCE induction. Such correlation was not apparent for CAs. These data suggest that the induction of SCEs by AA is associated with the metabolism of AA to GA and subsequent formation of depurinating DNA adducts; however, other mechanisms must be involved in the induction of CAs.
Lead is still widely used in many industrial processes and is very persistent in the environment. Although toxic effects caused by occupational exposure to lead have been extensively studied, there are still conflicting results regarding its genotoxicity. In a previous pilot study we observed some genotoxic effects in a population of lead exposed workers. Thus, we extended our study analysing a larger population, increasing the number of genotoxicity endpoints, and including a set of 20 genetic polymorphisms related to lead toxicokinetics and DNA repair as susceptibility biomarkers. Our population comprised 148 workers from two Portuguese factories and 107 controls. The parameters analysed were: blood lead levels (BLL) and δ-aminolevulinic acid dehydratase (ALAD) activity as exposure biomarkers, and T-cell receptor (TCR) mutation assay, micronucleus (MN) test, comet assay and OGG1-modified comet assay as genotoxicity biomarkers. Lead exposed workers showed markedly higher BLL and lower ALAD activity than the controls, and significant increases of TCR mutation frequency (TCR-Mf), MN rate and DNA damage. Oxidative damage did not experience any significant alteration in the exposed population. Besides, significant influence was observed for VDR rs1544410 polymorphism on BLL; APE1 rs1130409 and LIG4 rs1805388 polymorphisms on TCR-Mf; MUTYH rs3219489, XRCC4 rs28360135 and LIG4 rs1805388 polymorphisms on comet assay parameter; and OGG1 rs1052133 and XRCC4 rs28360135 polymorphisms on oxidative damage. Our results showed genotoxic effects related to occupational lead exposure to levels under the Portuguese regulation limit of 70 μg/dl. Moreover, a significant influence of polymorphisms in genes involved in DNA repair on genotoxicity biomarkers was observed.
: Because HIV is a fast-evolving virus, HIV genomic sequences of several individuals can be used to investigate whether they belong to a transmission network. Since the infamous 'Florida dentist case' in the beginning of the 1990s, phylogenetic analyses has been recurrently used in court settings as a forensic tool in HIV transmission investigations, for example cases where one or more complainants allege that a defendant has unlawfully infected them with HIV. Such cases can arise both in the context of HIV-specific criminal laws - in countries where transmission of HIV infection is specifically criminalized - or in the context of general laws, for example, by applying physical or sexual assault laws to HIV-related cases. Although phylogenetic analysis as a forensic technique for HIV transmission investigations has become common in several countries, the methodologies have not yet been standardized, sometimes giving rise to unwarranted conclusions. In this literature review, we revisit HIV court case investigations published in the scientific literature, as well as the methodological aspects important for the application and standardization of phylogenetic analyses methods as a forensic tool. Phylogenetic methodologies are improving quickly, such that more recently, phylogenetic relatedness, directionality of transmission and timing of nodes in the tree are used to assess whether the phylogenetic transmission analysis is consistent with or contradicting the charges. We find that there has been a lack of consistency between methods used in court case investigations and that it is essential to define guidelines to be used by phylogenetic forensic experts in HIV transmission cases in court.
To control the Human Immunodeficiency Virus (HIV) pandemic, the World Health Organization (WHO) set the 90-90-90 target to be reached by 2020. One major threat to those goals is late presentation, which is defined as an individual presenting a TCD4+ count lower than 350 cells/mm3 or an AIDS-defining event. The present study aims to identify determinants of late presentation in Europe based on the EuResist database with HIV-1 infected patients followed-up between 1981 and 2019. Our study includes clinical and socio-demographic information from 89851 HIV-1 infected patients. Statistical analysis was performed using RStudio and SPSS and a Bayesian network was constructed with the WEKA software to analyze the association between all variables. Among 89,851 HIV-1 infected patients included in the analysis, the median age was 33 (IQR: 27.0–41.0) years and 74.4% were males. Of those, 28,889 patients (50.4%) were late presenters. Older patients (>56), heterosexuals, patients originated from Africa and patients presenting with log VL >4.1 had a higher probability of being late presenters (p < 0.001). Bayesian networks indicated VL, mode of transmission, age and recentness of infection as variables that were directly associated with LP. This study highlights the major determinants associated with late presentation in Europe. This study helps to direct prevention measures for this population.
We examined differences in sexual risk behaviors, HIV prevalence, and demographic characteristics between men who have sex with men (MSM) who visit different types of venues to meet sexual partners, and identified correlates of high-risk behaviors. A cross-sectional behavioral survey was conducted with a venue-based sample of 1011 MSM in Portugal. Overall, 36.3 % of MSM usually visit cruising venues to meet sexual partners (63.7 % only visit social gay venues). Cruising venues' visitors reported higher HIV prevalence (14.6 % [95 % CI 11-18 %] vs. 5.5 % [95 % CI 4-7 %]). Visiting cruising venues was more likely among those older, reporting high number of male sexual partners, group sex, and unprotected anal sex with a partner whose HIV status was unknown. Cruising venues play an important role in increasing risk of HIV transmission among MSM who frequent them. Venue-focused behavioral interventions that promote healthy sexual behaviors are needed.
This cross-sectional bio-behavioral survey conducted with 853 female sex workers (FSW) aimed to examine differences in use of HIV health services, testing and prevalence among migrant and national FSW. A quarter of undocumented FSW had never used National Health Service (NHS) and 15 % never tested for HIV, significantly more than nationals (p < 0.001 and p = 0.024, respectively). HIV infection was self-reported by 11.9 % of nationals, 1.8 % of documented and 0.8 % of undocumented migrants (p < 0.001). The HIV rapid test was reactive in 13.6 % of undocumented, 8.0 % of nationals and 2.3 % of documented. A higher proportion of migrants were unaware of their positive serostatus compared to nationals. Ever had HIV testing was less likely among undocumented, who never used the NHS and who didn't know where to go if suspected being HIV-infected. Promoting early diagnosis with linkage to care among migrant FSW should be supported, while developing health services better tailored to their needs.
Background Exposure to pesticides is a major public health concern, because of the widespread distribution of these compounds and their possible long term effects. Recently, organic farming has been introduced as a consumer and environmental friendly agricultural system, although little is known about the effects on workers’ health. Objectives To evaluate genetic damage and immunological alterations in workers of both traditional and organic farming. Methods Eighty-five farmers exposed to several pesticides, thirty–six organic farmers and sixty-one controls took part in the study. Biomarkers of exposure (pyrethroids, organophosphates, carbamates, and thioethers in urine and butyrylcholinesterase activity in plasma), early effect (micronuclei in lymphocytes and reticulocytes, T-cell receptor mutation assay, chromosomal aberrations, comet assay and lymphocytes subpopulations) and susceptibility (genetic polymorphisms related to metabolism - EPHX1, GSTM1, GSTT1 and GSTP1 - and DNA repair – XRCC1 and XRCC2) were evaluated. Results When compared to controls and organic farmers, pesticide farmers presented a significant increase of micronuclei in lymphocytes (frequency ratio, FR=2.80) and reticulocytes (FR=1.89), chromosomal aberrations (FR=2.19), DNA damage assessed by comet assay (mean ratio, MR=1.71), and a significant decrease in the proportion of B lymphocytes (MR=0.88). Overall, organic farmers presented similar levels of genetic damage as controls, in some cases modulated by GSTT1 and GSTM1, GSTP1 105Ile/Ile and XRCC1 399Gln/Gln genotypes. Conclusions Results confirmed the increased presence of DNA damage in farmers exposed to pesticides, and showed as exposure conditions and genetic background influence observed effects. Findings from this study indicate that no evident genetic or immunologic damage can be observed in organic farmers.
BackgroundPortugal has one of the most severe HIV-1 epidemics in Western Europe. Two subtypes circulate in parallel since the beginning of the epidemic. Comparing their transmission patterns and its association with transmitted drug resistance (TDR) is important to pinpoint transmission hotspots and to develop evidence-based treatment guidelines.MethodsDemographic, clinical and genomic data were collected from 3599 HIV-1 naive patients between 2001 and 2014. Sequences obtained from drug resistance testing were used for subtyping, TDR determination and transmission clusters (TC) analyses.ResultsIn Portugal, transmission of subtype B was significantly associated with young males, while transmission of subtype G was associated with older heterosexuals. In Portuguese originated people, there was a decreasing trend both for prevalence of subtype G and for number of TCs in this subtype. The active TCs that were identified (i.e. clusters originated after 2008) were associated with subtype B-infected males residing in Lisbon. TDR was significantly different when comparing subtypes B (10.8% [9.5–12.2]) and G (7.6% [6.4–9.0]) (p = 0.001).DiscussionTC analyses shows that, in Portugal, the subtype B epidemic is active and fueled by young male patients residing in Lisbon, while transmission of subtype G is decreasing. Despite similar treatment rates for both subtypes in Portugal, TDR is significantly different between subtypes.
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