Philosophiae Doctor - PhD / There has been extensive growth in nanoscale technology in the last few decades to such a degree that nanomaterials (NMs) have become a constituent in a wide range of manufactured commercial and domestic products. This surge has resulted in uncertainties regarding their environmental impact, due to the significant increases in the amount of NMs released into the environment (Dowling et al., 2004) through intentional and unintentional releases. Like many other toxins, the aquatic environment is particularly vulnerable as it acts as a sink for nanoparticles (NPs) (Scown et al., 2010). The escalating growth of NMs has not advanced without efforts to understand its properties. Despite the dramatic advances in both the production and application of NMs, very little is known regarding their interaction with and effects on environmental and human health. Given the lack in scientific knowledge, particularly under various environmental conditions, it is often difficult to accurately assess the potential exposure pathways to ecological receptors of all NMs, silver nanoparticles (AgNPs) are the most widely used NPs, present in several consumer products mainly because of their anti-bacterial properties. It is estimated that the annual production exceeds 1000 tons/year (Piccinno et al., 2012). The increase uses of AgNPs in consumer products (e.g. textiles, cosmetics and personal hygiene), household appliances (e.g. washing machines and vacuum cleaners) and medical equipment have led to their increase release into the environment, thereby posing an environmental risk and human health concern. Silver NPs are known to induce the production of Reactive Oxygen Species (ROS) (Ahamed et al., 2010; Levard et al., 2012; Piao et al., 2011). Also since AgNPs are oxidized to ionic Ag (Ag+), it is still unclear whether the effects of ROS can be attributed to Ag+ release or to the AgNP itself (Fabrega et al., 2009; Miao et al., 2009). The behaviour of AgNPs is collectively influenced by inherent (nanoparticle size, shape, surface area, surface charge, crystal structure, coating, solubility/dissolution) and environmental factors (temperature, pH, ionic strength, salinity, organic matter). Climate change predictions indicate that the frequency, intensity and duration of extreme natural events (such as temperature elevations) will increase in the future (IPCC, 2001; IPCC, 2007). Global warming and climate change could increase atmospheric temperatures by 2.4 – 6.4 °C (IPCC, 2001; IPCC, 2007). The main feature associated with global climate change is the anticipation of wetter winters (i.e. increased flood events) and drier, warmer summers (i.e.extreme temperatures). These changes are likely to affect the inputs of contaminants into the environment as well as affect their behaviour, fate and transport, and toxicity in aquatic environments. It is known that the current temperature predictions in climate change scenarios could directly affect aquatic ecosystem communities (Carpenter et al., 1992), since temperature is also regarded as an important abiotic factor influencing growth and production of primary producers (i.e. algae, macrophytes etc.), and may also affect species distribution. For example, Liu et al. (2010) reported higher dissolution rates of AgNPs with increased temperature. Similarly, sudden hydrographic activity like high flood conditions may cause resuspension and redistribution of sediments. Few studies have linked the foreseeable climate change with contaminant release and ecosystem impacts. Similarly, few studies have analyzed the behaviour of NMs in the environment considering these predicted changes in mean temperatures. This thesis focuses on the effects of AgNPs on oxidative stress responses in the Cape River crab Potamonautes perlatus. The present work was undertaken to interpret the biological effects of AgNPs (< 100 nm) on P. perlatus, as well as to assess its effects under different environmental conditions. To understand the uptake, accumulation and biological effects of AgNPs, freshwater microcosms were produced to mimic a typical aquatic environment and temperature manipulated microcosms to which a commercially-available AgNP powder was added. Nanoparticles were characterized in the dry state and in suspension under different environmental conditions. Dissolution of total Ag was measured by inductively coupled plasma mass spectrometry (ICP-OES). Nanoparticle toxicity was assessed by measuring mortality and biomarkers of oxidative stress (CYP450, SOD, CAT, GST) evaluated in crab tissues. The overall results demonstrated that: (1) AgNPs may be transformed in both size and state under variable environmental conditions. The formation of smaller aggregates at higher temperatures suggests higher toxicity, (2) the release of free metal ions from NPs and NPs aggregates contribute to a higher toxicity towards aquatic organisms, (3) oxidative stress is a significant mechanism of AgNP toxicity and consequently enzymatic activation/inhibition with increasing AgNP concentration and temperatures, (4) oxidative stress responses to AgNPs particles were significantly modulated by temperature stress in P. perlatus, (5) mortality was observed from day 2 with maximum mortality achieved at day 7, (6) enzymes involved in detoxification, i.e. CYP450, has functional significance in the haemocytes, (7) P. perlatus has proved to be a significant target for AgNP exposure and, furthermore, has proved to be a suitable species to assess the ecotoxicity of AgNP in the aquatic environment, (8) antioxidant enzymes activities (are valuable tools to assess the oxidative status of crab tissues co-exposed to AgNPs and temperature. Furthermore, the results obtained in this study contributed to the understanding of the behaviour, bioavailability, uptake and toxicity of AgNPs under variable temperatures. / National Research Foundation (NRF) Thuthuka Fund and CSIR

abstract: Traumatic brain injury (TBI) affects an estimated 1.7 million people in the United States each year and is a leading cause of death and disability for children and young adults in industrialized countries. Unfortunately, the molecular and cellular mechanisms of injury progression have yet to be fully elucidated. Consequently, this complexity impacts the development of accurate diagnosis and treatment options. Biomarkers, objective signatures of injury, can inform and facilitate development of sensitive and specific theranostic devices. Discovery techniques that take advantage of mining the temporal complexity of TBI are critical for the identification of high specificity biomarkers. Domain antibody fragment (dAb) phage display, a powerful screening technique to uncover protein-protein interactions, has been applied to biomarker discovery in various cancers and more recently, neurological conditions such as Alzheimer’s Disease and stroke. The small size of dAbs (12-15 kDa) and ability to screen against brain vasculature make them ideal for interacting with the neural milieu in vivo. Despite these characteristics, implementation of dAb phage display to elucidate temporal mechanisms of TBI has yet to reach its full potential. My dissertation employs a unique target identification pipeline that entails in vivo dAb phage display and next generation sequencing (NGS) analysis to screen for temporal biomarkers of TBI. Using a mouse model of controlled cortical impact (CCI) injury, targeting motifs were designed based on the heavy complementarity determining region (HCDR3) structure of dAbs with preferential binding to acute (1 day) and subacute (7 days) post-injury timepoints. Bioreactivity for these two constructs was validated via immunohistochemistry. Further, immunoprecipitation-mass spectrometry analysis identified temporally distinct candidate biological targets in brain tissue lysate. The pipeline of phage display followed by NGS analysis demonstrated a unique approach to discover motifs that are sensitive to the heterogeneous and diverse pathology caused by neural injury. This strategy successfully achieves 1) target motif identification for TBI at distinct timepoints and 2) characterization of their spatiotemporal specificity. / Dissertation/Thesis / Doctoral Dissertation Neuroscience 2020

L’objectif du travail a été d’explorer la valeur pronostique pour les tumeurs de la vessie des polymorphismes de gènes associés à l’inflammation et du microenvironnement tumoral lymphocytaire CD8+. Pour les marqueurs constitutionnels, deux approches ont été conduites concomitamment, l’une explorant de façon globale les gènes associés à l’inflammation, l’autre ciblant un gène inflammatoire d’intérêt, PDL1, impliqué dans des points de contrôles immunologiques. A l’échelle du génome, en utilisant des méthodes statistiques soit classiques soit innovantes (dites multi marqueurs), nous avons démontré que les variants (SNP) dans les gènes TNIP1, CD5 et JAK3 étaient associés au risque de récidive des tumeurs de vessie non invasives du muscle alors que les variants dans les gènes MASP1, AIRE et CD3 étaient associés au risque de progression. Dans un deuxième temps, l’association entre variants dans le gène de PDL1 et pronostic des tumeurs de vessie a été explorée en appliquant une méthode classique « SNP par SNP » et une approche à l’échelle du gène. Nous avons identifié une forte association entre des variants de PDL1 et le pronostic de tumeurs de vessie envahissant le muscle dans une large cohorte prospective, mais sans pouvoir répliquer ce résultat dans une série issue du consortium TCGA.Dans les tumeurs n’envahissant pas le muscle, nous avons développé et évalué une méthode d’évaluation standardisée de l’infiltrat lymphocytaire CD8+, cellules T-cytotoxiques impliquées dans la mort des cellules tumorales. L’analyse morphométrique après double immuno-marquage des cellules tumorales et des lymphocytes CD8+ et numérisation a permis d’estimer de façon séparée le compte des cellules inflammatoires dans la tumeur et le stroma, et d’estimer l’hétérogénéité spatiale intra-tumorale. Nous avons montré que cette hétérogénéité limite les estimations de l’infiltrat CD8+ sur les puces tissulaires (Tissue Micro Array) qui échantillonnent les tumeurs de façon restrictive. Sous cette réserve, nous avons identifié dans les tumeurs n’envahissant pas le muscle une association entre l’infiltrat lymphocytaire CD8+ et le stade tumoral Ta/T1, ainsi qu’avec le risque de récidive des tumeurs T1. A l’avenir, variations génétiques constitutionnelles dans les gènes de l’inflammation et évaluation de l’infiltrat tumoral inflammatoire pourraient être intégrées en vue d’améliorer la prédiction du pronostic des tumeurs vésicales. / The aim of this study was to explore prognostic value for bladder cancer of germline polymorphisms in inflammatory genes and tumor CD8+ lymphocytic microenvironment. For constitutional markers, two approaches were conducted jointly: one genome-based using specific GWAS statistical methods, the other gene-based focusing on PDL1, an inflammatory gene implicated in immune checkpoints. At the genome level, using both standard and innovative statistical methods (multi marker methods Bayesian Lasso and Bayes A) we demonstrated that variants (SNPs) in TNIP1, CD5 and JAK3 were associated with the risk of recurrence of non-muscle invasive bladder cancer (NMIBC) while SNPs in MASP1, AIRE and CD3 were associated with risk of progression. Meanwhile, association between PDL1 and prognosis of NMIBC and muscle invasive BC (MIBC) was explored using classical SNPS by SNP investigations and a gene based approach. We identified a very strong association between PDL1 variants and MIBC prognosis in a large prospective cohort but failed replicating those results in the TCGA consortium series.In non-muscle invasive bladder cancer, we developed and evaluated a standardized counting approach of CD8+ cells, T-cytotoxic lymphocytes implicated in tumor cells death. Morphometric analysis after double immuno-staining of tumor cells and digitalization allowed separate estimation of CD8+ cells in the tumor and stroma compartment and estimation of spatial intra tumoral heterogeneity. We demonstrated that this heterogeneity compromised CD8+ estimation on Tissue Micro Arrays, which sample the tumors in a restrictive manner. Keeping those limitations in mind, we identified an association between CD8+ inflammatory infiltrate and both NMIBC stage and T1 tumours risk of recurrence. In the future, germline variation in inflammatory genes and evaluation of tumor inflammatory infiltrate could be integrated for better prediction of bladder cancer prognosis.

Identification et caractérisation d'une population d'ILC2 associée à la sévérité de la rhinite allergique et de l'asthmeTrois catégories de cellules lymphoïdes innées (innate lymphoid cells, ILC) ont été décrites récemment sur la base de leurs phénotypes et leurs caractéristiques fonctionnelles : les ILC1, ILC2 et ILC3. Les ILC2 semblent avoir un rôle pro-inflammatoire important dans l’allergie en raison de leur capacité à produire de grandes quantités de cytokines TH2.Pour mieux comprendre le rôle de ces cellules dans l’allergie respiratoire, nous avons comparé les ILC sanguines de patients atteints d’une rhinite allergique associée ou non à un asthme, à celles de sujets non allergiques. Cette étude révèle de multiples différences fonctionnelles entre les ILC circulantes de sujets sains et allergiques. Notamment, la fréquence d’ILC2 exprimant le récepteur aux chimiokines CCR10 est augmentée dans le sang de patients asthmatiques sévères.CCR10 pouvant permettre le recrutement des ILC vers les organes cibles, le rôle des ILC2 CCR10+ dans la physiopathologie de l’asthme a été étudié. Leur présence dans les poumons humains a été observée. Des analyses fonctionnelles et phénotypiques ont révélé que cette sous-population cellulaire était peu activée mais présentait une plasticité leur conférant des caractéristiques proches des ILC1. La déplétion de ces cellules dans un modèle murin d’asthme allergique aggrave l’hyperréactivité bronchique.Les travaux de cette thèse documentent le rôle des ILC dans l’asthme. En particulier, la fréquence sanguine d’ILC2 CCR10+ augmente avec la sévérité de la maladie. Les résultats obtenus dans les modèles animaux suggèrent que ces cellules auraient un rôle bénéfique dans le contrôle de l’asthme. La voie du CCR10 pourrait représenter une nouvelle cible pour le développement de traitements innovants contre l’asthme ou une source prometteuse de biomarqueurs. / Identification and characterization of an ILC2 subset linked to allergic rhinitis and asthma severityInnate lymphoid cells (ILCs) have been classified into ILC1, ILC2 and ILC3 subsets based on their respective phenotypes and functions. Considering the strong ability of ILC2s to produce TH2 cytokines, these cells likely play a significant role in allergic diseases.To better understand the role of these cells in respiratory allergies, we compared blood ILCs from allergic patients with or without asthma to non-allergic individuals. Together our results show multiple functional differences between ILC from allergic and healthy subjects. In particular, ILC2s expressing the chemokine receptor CCR10 are specifically enriched in the blood of patients with severe allergic asthma.Considering that CCR10 could allow the recruitment of ILCs to target organs, the role of CCR10+ ILC2s in asthma physiopathology has been studied. This ILC2 subtype is present in human lungs. Functional and phenotypic analyses revealed that these cells are less activated than other ILC2s and show ILC1-like properties. CCR10+ ILC2s depletion in a mouse model of allergic asthma exacerbate airway hyperreactivity.Together, this work documents the role of ILCs in asthma. Specifically, circulating CCR10+ ILC2 frequency increases with asthma severity. The results obtained in mouse models suggest that these cells could have a beneficial role in asthma control. CCR10 pathway could represent a new target to elaborate breakthrough treatments against asthma or a source of promising biomarkers.

The aim of this thesis was to develop and validate prognostic and predictive biomarkers in order to better identify among patients with metastatic colorectal cancer those at high-risk of early death or progression. The interest in developing such biomarkers is that their subsequent use in clinical practice would avoid exposing a patient for months to the toxic side effects of ineffective and expensive treatments, and thus to limit the financial impact of these treatments on our healthcare systems.The projects carried out in the framework of this thesis have shown that:The biomarker WB-MATV (metabolically active tumor volume of the whole body) measured before the start of the last line treatment has a high prognostic value, higher than the general clinical parameters commonly used. This biomarker was then validated in first line treatment and was shown to have a high prognostic value, also higher than the general clinical parameters.The biomarker cfDNA (circulating DNA) also representing the tumor load was then investigated to assess its value added to the previously validated WB-MATV. We showed that the presence of high levels of cfDNA before starting the last-line treatment is significantly associated with poor prognosis and that these two biomarkers are prognostically complementary, each providing an added value.The biomarker of early metabolic response to last line treatment has a high negative predictive value (95%). This biomarker was then validated as a predictive biomarker independent of WB-MATV and clinical factors in first-line treatment setting.In conclusion, the results of this thesis strongly support the clinical use of these prognostic and predictive biomarkers in patients with metastatic colorectal cancer. Allowing a more accurate stratification of patients, the use of the combination of these biomarkers should become an essential tool to help oncologists in tailoring therapeutic strategies according to the patients’ individual risk. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished

Receiving a breast cancer (BC) diagnosis generates significant physical and psychological stress that may persist months, years, or even decades beyond treatment completion. Such chronic stress can severely alter the biological systems of BC survivors (BCS). Yet, little is known about the impact and associated variables of these long-term physiological sequelae. Considering that the number of BCS continues to grow each year, it is imperative to assess the extent to which a BC experience impacts human physiological mechanisms by examining the secretion patterns of associated stress- and immune-related biomarkers and by exploring the behavioural, physical, and psychological variables implicated in these dysregulations. Such research is of particular importance in order to guide cancer survivorship care and develop interventions promoting optimal health outcomes in BCS. This research program sought to address this through three inter-related studies. Study One was a quasi-experimental design study examining both the diurnal and reactive concentration patterns of secretory immunoglobulin A (SIgA) in a sample of women with (n = 22) and without a prior history of BC (n = 26). SIgA concentration patterns were contrasted to concentration patterns of cortisol and salivary alpha-amylase (sAA) in the same individuals (complementary to two previously published studies). Participants supplied saliva samples at five time points on two consecutive typical days (for diurnal data) and at seven time points before, during, and after an acute laboratory stressor (for reactive data). Results reveled no evidence of uncharacteristic SIgA diurnal or reactive concentration patterns, suggesting a normal and well-functioning immunological SIgA system in BCS on average 4.6 years post-diagnosis. Study One acted as a summary article allowing readers to grasp the "big picture" of long-term physiological dysregulations in BCS as a whole. Building on this, Study Two, which used the same dataset as Study One, aimed to determine whether physical activity (PA) could mitigate the adverse physiological effects of a BC experience in BCS (n = 25), as indexed by their cortisol concentration patterns. Participants self-reported their PA frequency and engaged in the same cortisol assay protocol reported in Study One. Results indicated no statistically significant differences in diurnal and reactive cortisol patterns between low- and high-PA groups. A trend that PA might not have the same effect on women with and without a history of BC was noted. Important limitations to Study Two included the small sample size and the lack of sensitivity and objectivity of the PA measure. To address Study Two’s limitations and to consider a wider range of modifiable variables that could contribute to the physiological dysregulations observed in BCS, Study Three aimed to assess the predictive value of six behavioural, physical, and psychological variables on the physiological effects of a BC experience, as indexed by cortisol (n = 192) and C-reactive protein (CRP; n = 168) levels over the first 1.5 year post-treatment. CRP, a biomarker that had not been considered so far in this research program, allowed to assess systemic inflammation in BCS post-treatment. Study Three also aimed to describe naturally occurring changes in cortisol and CRP levels and assess whether they changed in tandem. Data were drawn from 201 BCS who provided capillary blood and saliva samples at approximately 3.5 months post-treatment and again 3, 6, 9, and 12 months later. At each time point, participants also completed self-report questionnaires and wore an accelerometer for seven consecutive days. Multilevel modeling analyses revealed no significant change over time for cortisol levels post-treatment and a non-linear trajectory of change for CRP levels which was not predicted by cortisol levels. Associations between cortisol and sedentary time as well as associations between CRP and PA, body mass index, and health- and cancer-related stress were found. Collectively, these three inter-related studies uniquely add to the literature by describing long-term physiological trajectories of stress- and immune-related biomarkers in BCS. This research program attempts to gain a better understanding of the underlying mechanisms that tie behavioural, physical, and psychological variables and biomarker secretion to a BC experience. It also offers opportunities to identify women at greater risk of physiological dysregulations following a BC experience. This represents an important step towards the development of tailored interventions targeting specific BCS that most warrant them. With the number of BCS climbing each year, cancer survivorship needs to be a priority in research and efforts to better understand, monitor, and mitigate the physiological consequences of a BC experience are critical.

Les cancers du poumon non à petites cellules (CPNPC) restent une cause majeure de mortalité par cancer, malgré l’apport de thérapies moléculaires ciblées et des immunothérapies. La survie des patients aux stades avancés reste limitée et la mise au point de biomarqueurs pronostiques permettant de stratifier les patients ou prédictifs de réponse à différents types de traitement constitue un enjeu important pour la prise en charge des patients.La mise au point de biomarqueurs obéit à des enjeux spécifiques tenant à la connaissance de la biologie tumorale dans des domaines complexes tels que celui de la réparation de l’ADN, aux caractéristiques des outils disponibles pour créer ces biomarqueurs et à leur applicabilité dans le contexte clinique.Dans le cadre de cette thèse, il a été étudié la manière dont l’expression de la protéine PARP1 peut s’intégrer aux biomarqueurs pronostiques de réparation de l’ADN dans les CPNPC. Il a par ailleurs été étudié le rôle de la protéine MMS19, identifiée à partir d’études d’expression génique, comme biomarqueur prédictif potentiel de réponse au cisplatine dans les CPNPC. Enfin, l’utilisation des cellules tumorales circulantes pour le développement de biomarqueurs a été étudiée dans le cadre de la détection des remaniements du gène ALK, une altération oncogénique constituant une cible thérapeutique dans les CPNPC. / Non-small cell lung cancers (NSCLC) remain a leading cause of cancer-related death despite the advent of targeted therapies and immunotherapies. At advanced stages, patient survival remains limited and establishment of new biomarkers, either prognostic for patient stratification or predictive of response to various therapies, is an important goal for patient’s treatment.Development of biomarkers is dependent on many components among which: knowledge of cancer cell biology in complex cellular processes such as DNA repair, characteristics of tools available to create biomarkers and applicability in daily medical practice.In this thesis, expression of PARP1 has been evaluated as a prognostic biomarker in NSCLC, in the broader context of DNA repair biomarkers. The biological and clinical relevance of MMS19 protein, identified in gene expression analysis , as a biomarker for cisplatin sensitivity in NSCLC has also been studied. Finally, the use of circulating tumor cells for biomarker development has been studied through the detection of ALK gene rearrangment, an oncogenic targetable alteration in NSCLC.

Philosophiae Doctor - PhD / Wastewater is normally composed of a mixture of pollutants. The type and composition of pollutants in a particular wastewater depend on the source of origin. The source and characteristics of a particular wastewater determine the ideal method of sewage treatment. Specific treatment techniques are effective in the removal of certain types of pollutants and may have no impact on the levels of other types of pollutants. Therefore, a combination of treatments and assessment of the quality of effluent before release into the environment is normally recommended. The assessment of effluent can be achieved by various techniques including chemical analysis and biological assays. Chemical analyses are commonly employed; however, they often pose detection problems and are considered to be uneconomical.

<p><b><i>Background and Objective:</i></b> Pb is a well-known toxic metal that can accumulate in bones over time and still threatening large populations nowadays, even those who are environmentally exposed to it. Strontium (Sr) is a metal directly related to bone health and has been used in the treatment of osteoporosis disease as a supplement. Manganese (Mn) is an essential nutrient in the body, yet excessive Mn is toxic and affecting many organ systems. Another toxic metal, mercury (Hg), has been poising different populations primarily through seafood consumptions, especially inducing neurological disorders in infants and fetuses. Even though significant associations between the above metal exposures and health outcomes have been recognized over the decades, the current technologies are limited in assessing cumulative long-term exposures <i>in vivo</i> to evaluate such associations further. Bone and toenail are appropriate biomarkers to reflect long-term exposure due to the longer half-life of these metals in them than in the traditional biomarkers. Therefore, this work evaluated the usefulness of portable x-ray fluorescence (XRF) technology on <i>in vivo</i> quantification of Pb and Sr in bone, and Mn and Hg in toenail.</p> <p><b><i>Materials and Methods:</i></b> The portable XRF device was calibrated by using the Pb- and Sr-doped bone-equivalent phantoms, and Mn- and Hg-doped nail-equivalent phantoms, correspondingly in different projects. Seventy-six adults (38-95 years of age, 63 ± 11 years) from Indiana, USA, were recruited to participate in this study. For the <i>in vivo</i> bone measurements, each participant was measured at the mid-tibia bone using the portable XRF and K-shell XRF system (KXRF). We estimated the correlation between the bone Pb concentration measured by both devices to evaluate the use of the portable XRF in the bones. Using the portable XRF, the bone Sr exposure of the study population were simultaneously assessed with the bone Pb exposures. Besides, we analyzed the mid-tibia bone Sr data of a Chinese population, which were measured with the same portable XRF device by our research group. We also examined the extent to which the detection limit (DL) of the portable XRF was influenced by scan time and overlying soft tissue thickness for both Pb and Sr. </p> <p>For the exposure assessment of Mn and Hg in toenails, we first established system calibrations and determined the DL with phantoms. In order to validate the portable XRF in a population study, the recruited participants were measured at the big toenail by the device, and their toenail clippings were analyzed by the inductively coupled plasma spectrometry (ICP-MS). Besides, we analyzed the toenail data of an occupationally-exposed population, collected by our collaborators in Boston. A portable XRF device with the same model as ours was used in that study. </p> <p><b><i>Results:</i></b> The uncertainty of <i>in vivo</i> individual bone measurement increased with higher soft tissue thickness overlying bone, and reduced with extending measurement time. With thickness ranging from 2 to 6 mm, the uncertainty of a 3-minute <i>in vivo</i> measurement ranged from 1.8 to 6.3 ug/g (ppm) for bone Pb and from 1.3 to 2.3 ppm for bone Sr. Bone Pb measurements via portable XRF and KXRF were highly correlated: R=0.48 for all participants, and R=0.73 among participants with soft tissue thickness < 6 mm (72% of the sample). A trend of different bone Sr concentrations was observed across the races and sexes. </p> <p>The DL of the portable XRF with 3-minute toenail measurements was 3.59 ppm for Mn and 0.58 ppm for Hg. The portable XRF and ICP-MS measurements were highly correlated in the occupational populations for both Mn (R = 0.59) and Hg (R = 0.75). A positive correlation (R = 0.34) was found for toenail Mn measurements in the environmentally-exposed population, while a non-significant correlation was observed for toenail Hg due to the extremely low-level of Hg (Mean = 0.1 ppm) in the study population. </p> <p><b><i>Discussion and Conclusion:</i></b> The portable XRF could be a valuable tool for non-invasive <i>in vivo</i> quantification of bone Pb and Sr, especially for people with thinner soft tissue; and of toenail Mn and Hg, especially for people with moderate- to high-level exposures. </p>

Aim: The aim of this literary study is to investigate the incidence and causal factors of periodontitis among individuals ≥50 years of age with coronary heart disease. Method: The method used for this literary study was to search for original scientific articles in the databases CINAHL, DOSS and MEDLINE. Relevant keywords were used for the search in the databases with restriction for the selection with inclusion and exclusion criteria. Original scientific articles were quality reviewed, medium and high quality of the articles were included. Results: The study shows a link between periodontitis and coronary heart disease. The severity of periodontitis affects the onset and progression of coronary heart disease. Factors that affect disease development are the inflammatory process and its biomarkers (interleukins and adiponectin) as well as age and specific periodontal bacteria. Conclusion: The result of this literary study shows a connection between the occurrence of periodontitis and coronary heart disease. Common risk factors for the diseases that has been identified are the inflammatory process, inflammatory biomarkers, age and oral bacteria.