RESUMO
Interleukin 32 (IL-32) is a potent multi-isoform proinflammatory cytokine, which is upregulated in people with HIV (PWH) and is associated with cardiovascular disease (CVD) risk. However, the impact of IL-32 isoforms on CD4 T-cell cardiotropism, a mechanism potentially contributing to heart inflammation, remains unknown. Here we show that IL-32 isoforms ß and γ induce the generation of CCR4+CXCR3+ double positive (DP) memory CD4 T-cell subpopulation expressing the tyrosine kinase receptor c-Met, a phenotype associated with heart-homing of T cells. Our ex vivo studies on PWH show that the frequency of DP CD4 T cells is significantly higher in individuals with, compared to individuals without, subclinical atherosclerosis and that DP cells from antiretroviral-naive and treated individuals are highly enriched with HIV DNA. Together, these data demonstrate that IL-32 isoforms have the potential to induce heart-homing of HIV-infected CD4 T cells, which may further aggravate heart inflammation and CVD in PWH.
Assuntos
Linfócitos T CD4-Positivos , Infecções por HIV , Interleucinas , Feminino , Humanos , Masculino , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular , DNA Viral , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1 , Interleucinas/metabolismo , Interleucinas/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMO
BACKGROUND: Reported cases of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are increasing among Canadian men. Estimates of community-based CT/NG prevalence are lacking among gay, bisexual, and other men who have sex with men (GBM). METHODS: Respondent driven sampling was used to recruit GBM in Montréal, Canada between February 2017 and June 2018. Specimens provided from urogenital, rectal, and pharyngeal sites were analyzed using nucleic acid amplification test to detect CT/NG. Prevalence estimates of CT/NG, overall and by anatomical site were calculated. All estimates are respondent-driven sampling-adjusted. RESULTS: Among 1177 GBM, the prevalence of rectal, urogenital, pharyngeal and overall were respectively 2.4%, 0.4%, 0.4%, and 2.8% for CT infections, and 3.1%, 0.4%, 3.5%, and 5.6% for NG infections. If testing had been limited to the urogenital site, 80% and 94% of CT and NG infections, respectively, would have been missed. CONCLUSIONS: This community-based study among GBM shows that the CT prevalence was about half of that observed for NG. A large part of CT/NG infections involves only the extragenital sites, highlighting the need for systematic multisite screening regardless of symptoms. In the mist of the COVID-19 pandemic and the limited CT/NG screening capacity due to test kits shortage, it might be considered to prioritize rectal and pharyngeal CT/NG testing over urogenital testing in asymptomatic GBM.
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COVID-19 , Infecções por Chlamydia , Gonorreia , Minorias Sexuais e de Gênero , Canadá/epidemiologia , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/genética , Gonorreia/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Neisseria gonorrhoeae/genética , Pandemias , Prevalência , SARS-CoV-2RESUMO
Few ecotoxicity studies are available on thorium (Th) which hinders the ability to evaluate its ecotoxicological risk. Its release in the environment is often associated with the extraction of rare earth elements and uranium, as well as the field applications of phosphate fertilizers. This study investigates the effects of Th on microbial communities of periphytic biofilms. Ceramic plates were left to colonize for one month in the laboratory with a biofilm sampled from Cap Rouge river (QC, Canada). Plates were randomly placed in channels containing culture media representing three different conditions: a control condition (C0; background Th concentrations of 0.004 ± 0.002 nM), a low Th concentration condition (C1; 0.18 ± 0.09 nM Th) and a moderately high Th condition (C10; 8.7 ± 3.4 nM) for up to 4 weeks. The presence of Th modified the diatom community by changing its taxonomic structure, reducing diversity and increasing cell density. The taxonomic structure of the bacterial community, followed by 16S metabarcoding analysis, was affected with a significant decrease in Pseudanabaena and Shingopyxis genera in the two Th exposed conditions. No direct toxic effect of Th was observed on counted micromeiofauna but the changes in diatom and bacterial communities could explain the higher number of individual diatoms and micromeiofauna observed in Th-exposed conditions. This work shows that low concentrations of Th can modify biofilm structure, which, in turn, could disturb its ecologically key functions.
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OBJECTIVES: Assess carotid artery strain and motion in people living with HIV as markers of premature aging using ultrasound noninvasive vascular elastography (NIVE). METHODS: Seventy-four HIV-infected and 75 age-matched control subjects were recruited from a prospective, controlled cohort study from October 2015 to October 2017 (mean age 56 years ± 8 years; 128 men). NIVE applied to longitudinal ultrasound images of common and internal carotid arteries quantified the cumulated axial strain, cumulated shear strain, cumulated axial translation, and cumulated lateral translations. The presence of plaque was also assessed. An association between elastography biomarkers and HIV status was evaluated with Mann-Whitney tests and multivariable linear regression models. RESULTS: A higher occurrence of carotid artery plaques was found in HIV-infected individuals (p = 0.011). Lower cumulated lateral translations were found in HIV-infected subjects on both common and internal carotid arteries (p = 0.037 and p = 0.026, respectively). These observations remained significant when considering multivariable models including common cardiovascular risk factors and clinical characteristics (p < 0.05). Lower cumulated axial strains were also observed in internal carotid arteries when considering both multivariable models (p < 0.05). CONCLUSION: Lower translation and strain of the carotid artery wall in HIV-infected individuals indicates increased vessel wall stiffness. These new imaging biomarkers could be used to characterize premature atherosclerosis development. KEY POINTS: ⢠Noninvasive vascular elastography (NIVE) based on ultrasound imaging quantifies translations and strains of carotid arteries. ⢠Lower translation and strain of the carotid artery wall found in HIV-infected individuals indicate premature arterial stiffening, compared with age-matched controls. ⢠Carotid artery plaques were more prevalent in HIV-infected individuals than in control subjects.
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Artérias Carótidas/diagnóstico por imagem , Artérias Carótidas/fisiopatologia , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/fisiopatologia , Técnicas de Imagem por Elasticidade/métodos , Infecções por HIV/complicações , Rigidez Vascular , Adulto , Artéria Carótida Primitiva/diagnóstico por imagem , Artéria Carótida Interna/diagnóstico por imagem , Estenose das Carótidas/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , UltrassonografiaRESUMO
A lack of knowledge on metal speciation in the microenvironment surrounding phytoplankton cells (i.e., the phycosphere) represents an impediment to accurately predicting metal bioavailability. Phycosphere pH and O2 concentrations from a diversity of algae species were compiled. For marine algae in the light, the average increases were 0.32 pH units and 0.17 mM O2 in the phycosphere, whereas in the dark the average decreases were 0.10 pH units and 0.03 mM O2, in comparison to bulk seawater. In freshwater algae, the phycosphere pH increased by 1.28 units, whereas O2 increased by 0.38 mM in the light. Equilibrium modeling showed that the pH alteration influenced the chemical species distribution (i.e., free ion, inorganic complexes, and organic complexes) of Al, Cd, Co, Cu, Fe, Hg, Mn, Ni, Pb, Sc, Sm, and Zn in the phycosphere, and the O2 fluctuation increased oxidation rates of Cu(I), Fe(II) and Mn(II) from 2 to 938-fold. The pH/O2-induced changes in phycosphere metal chemistry were larger for freshwater algae than for marine species. Reanalyses of algal metal uptake data in the literature showed that uptake of the trivalent metals (Sc, Sm and Fe), in addition to divalent metals, can be better predicted after considering the phycosphere chemistry.
Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Disponibilidade Biológica , Metais , Fitoplâncton , Água do Mar , Poluentes Químicos da Água/análiseRESUMO
Little attention has been paid to the role of essential trace elements on the toxicity of another element. In this work, we examined if low concentrations of essential elements (Co, Mn, Zn, and Fe) modified the response of a freshwater green alga ( Chlamydomonas reinhardtii) to copper. To do so, we followed cell growth over 72 h in exposure media where the essential element concentrations were manipulated. Among these elements, iron proved to have a strong impact on the cells' response to copper. The free Cu2+ concentrations required to inhibit cellular growth by 50% (EC50) over 72 h decreased from 2 nM in regular Fe medium (10-17.6 M Fe3+) to 4 pM in low iron medium (10-19.0 M Fe3+); a 500-fold increase in toxicity. Moreover, at low Cu2+ concentrations (10-13.0 to 10-10.5 M), Cu uptake increased under low iron conditions but remain relatively stable under regular iron conditions. These results show clearly that iron plays a protective role against copper uptake and toxicity to C. reinhardtii. In freshwaters, iron is always abundant but the expected free iron concentrations in surface waters can vary between 10-14.0 to 10-20.0 M, depending on pH (e.g., when pH increases from 6 to 8). We conclude that copper toxicity in natural waters can be modulated by iron and that, in some conditions, the Biotic Ligand Model may need to be further developed to account for the influence of iron.
Assuntos
Chlamydomonas reinhardtii , Oligoelementos , Cobre , Água Doce , FerroRESUMO
Low-molecular-weight weak ligands such as cysteine have been shown to enhance metal uptake by marine phytoplankton in the presence of strong ligands, but the effect is not observed in freshwater. We hypothesized that these contrasting results might be caused by local cysteine degradation and a Ca effect on metal-ligand exchange kinetics in the boundary layer surrounding the algal cells; newly liberated free metal ions cannot be immediately complexed in seawater by Ca-bound strong ligands but can be rapidly complexed by free ligands at low-Ca levels. The present results consistently support this hypothesis. At constant bulk Cd2+ concentrations, buffered by strong ligands: (1) at 50 mM Ca, cysteine addition significantly enhanced Cd uptake in high-Ca preacclimated euryhaline Chlamydomonas reinhardtii (cultured with cysteine as a nitrogen source to enhance local Cd2+ liberation via cysteine degradation); (2) at 0.07 mM Ca, this enhancement was not observed in the algae; (3) at 50 mM Ca, the enhancement disappeared when C. reinhardtii were cultured with ammonium (to inhibit cysteine degradation and local Cd2+ liberation); (4) cysteine addition did not enhance Cd uptake by cysteine-cultured marine Thalassiosira weissflogii when the concentration of immediately reacting strong ligands was sufficient to complex local Cd2+ liberation.
Assuntos
Cisteína , Fitoplâncton , Cádmio , Água Doce , Metais , Água do MarRESUMO
Good outcomes with kidney and liver transplantation in HIV-positive patients have led clinicians to recommend lung transplantation in HIV-positive patients based on extrapolated data. Pre-transplant mycobacterial infection is associated with an increased risk of developing new infection or aggravating existing infection, though it does not contraindicate transplantation in non-HIV-infected patients. However, no data exists regarding the outcome of HIV-positive patients with pre-transplant mycobacterial infection. We report a case of double lung transplantation in a 50-year-old HIV-positive patient with alpha-1 antitrypsin deficiency. Prior to transplantation, Mycobacterium kansasii was isolated in one sputum culture and the patient was considered merely colonized as no clinical evidence of pulmonary or disseminated disease was present. The patient successfully underwent a double lung transplantation. Nontuberculous mycobacterial infection was diagnosed histologically on examination of native lungs. Surveillance and watchful waiting were chosen over treatment of the infection. HIV remained under control post-transplantation with no AIDS-defining illnesses throughout the follow-up. A minimal acute rejection that responded to increased corticosteroids was reported. At 12 months post-transplant, a bronchiolitis obliterans syndrome was diagnosed after a drop in FEV1. No evidence of isolation nor recurrence of nontuberculous mycobacteria was reported post-transplantation. At 15 months post-transplant, the patient remained stable with an FEV1 of 30%. The presence of pre-transplant nontuberculous mycobacterial infection did not translate into recurrence of nontuberculous mycobacterial infection post-transplant. Whether it contributed to bronchiolitis obliterans syndrome remains unknown.
Assuntos
Antirretrovirais/uso terapêutico , Infecções por HIV/tratamento farmacológico , Transplante de Pulmão , Infecções por Mycobacterium não Tuberculosas/terapia , Mycobacterium kansasii/isolamento & purificação , Deficiência de alfa 1-Antitripsina/cirurgia , Idoso , Antibacterianos/uso terapêutico , Comorbidade , HIV/efeitos dos fármacos , HIV/isolamento & purificação , Infecções por HIV/complicações , Infecções por HIV/virologia , Humanos , Pulmão/diagnóstico por imagem , Pulmão/microbiologia , Pulmão/cirurgia , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/complicações , Infecções por Mycobacterium não Tuberculosas/diagnóstico por imagem , Infecções por Mycobacterium não Tuberculosas/microbiologia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Carga Viral/efeitos dos fármacos , Deficiência de alfa 1-Antitripsina/complicações , Deficiência de alfa 1-Antitripsina/diagnóstico por imagemRESUMO
Aluminum (Al) is widespread in the environment including the ocean. The effects of Al on marine organisms have attracted more and more attention in recent years. However, the mechanisms of uptake of Al by marine organisms and the subcellular distribution of Al once assimilated are unknown. Here we report the uptake and subcellular distribution of Al in a marine diatom Thalassiosira weissflogii. Short-term (<â¯120â¯min) uptake experiments showed that the Al uptake rate by the diatom was 0.033⯱â¯0.013 fmol-1 cell-1 min-1 (internalization flux normalized to the exposure Al concentration of 2⯵Mâ¯=â¯0.034⯱â¯0.013â¯nmolâ¯m-2 min-1 nM-1). Subcellular fractionation experiments showed that the internalized Al was partitioned to subcellular components in the following order: granules (69⯱â¯5%) >â¯debris (17⯱â¯4%) >â¯organelles (12⯱â¯2%) >â¯heat-stable peptides (HSP) (~2%) >â¯heat-denaturable proteins (HDP) (<â¯1%), indicating that the majority of intracellular Al was detoxified and stored in inorganic forms. The subcellular distribution of Al in the diatom is different from that of Al in freshwater green algae, in which most of the internalized Al is partitioned to organelles. We also evaluated an artificial seawater-based EDTA rinse solution to remove Al adsorbed on the diatom cell surface. Overall, our study provides new information to understand the mechanisms of uptake of Al by marine diatoms, and the mechanisms responsible for the biological effects (both toxic and beneficial) of Al on the growth of marine phytoplankton, especially diatoms.
Assuntos
Alumínio/metabolismo , Diatomáceas/efeitos dos fármacos , Água do Mar/química , Poluentes Químicos da Água/metabolismo , Adsorção , Alumínio/análise , Alumínio/toxicidade , Diatomáceas/metabolismo , Fitoplâncton/efeitos dos fármacos , Fitoplâncton/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
The aim of this research was to assess the ecotoxicity of leachates originating from a niobium mine located in Canada. These tailings contain considerable amounts of carbonates and phosphates and could potentially be used as fertilizer for agriculture. However, the presence of different contaminants linked with the ores mined, including rare earth elements and daughter elements of the uranium disintegration chain is of concern. Bioassays have been used to determine if the tailings leachates could be harmful. The assessment of the toxicity of progressive dilutions of five tailing leachates (808, 809, 810, 811 and 897) was performed on different organisms: phytoplankton Raphidocelis subcapitata and duckweed Lemna minor, based on their growth and chlorophyll a content, and water flea Daphnia magna based on their mobility, mortality and reproduction. Overall, the leachates showed higher toxicity to Raphidocelis subcapitata and Lemna minor, than toward Daphnia magna. Leachate 808 showed no toxicity to all organisms while leachate 810 showed significant effects to all species. The results can be explained by the leachate dissolved metal or nutrient concentrations, but also by the metal bioavailability which depends on pH and hardness. Generally, toxicity was observed in undiluted samples tested, which is not representative of the conditions that could occur in the environment. This supports the idea that these tailings could be used as fertilizer albeit more studies may be required, particularly to assess the toxicity of the tailings leachate for benthic organisms, the toxicity of the tailings for terrestrial organisms and the variations of soil and sediment physicochemical properties after tailing treatments.
Assuntos
Organismos Aquáticos/efeitos dos fármacos , Mineração , Nióbio , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/metabolismo , Araceae/efeitos dos fármacos , Araceae/metabolismo , Disponibilidade Biológica , Canadá , Clorofila A/metabolismo , Daphnia/efeitos dos fármacos , Daphnia/metabolismo , Fitoplâncton/efeitos dos fármacos , Fitoplâncton/metabolismo , Poluentes Químicos da Água/químicaRESUMO
In this study we tested the hypothesis that metal uptake by unicellular algae may be affected by changes in metal speciation in the boundary layer surrounding the algal cells. The freshwater alga Chlamydomonas reinhardtii was preacclimated to different N nutrition regimes; changes in N nutrition are known to change the nature of extracellular metabolites (e.g., reactive oxygen species "ROS", and OH-) and thus boundary layer chemical conditions. Specifically, at a constant bulk free Cd2+ concentration, Cd uptake by N-starved algae in cysteine-buffered solution was significantly higher than that in NTA-buffered solution. This enhancement was likely due to an increase of the free Cd2+ concentration in the boundary layer, resulting from localized cysteine oxidation by ROS released from these algae. On the other hand, Cd uptake was markedly lower when the free Cd2+ concentration near cell surface decreased as a result of an increase in the boundary layer pH of nitrate-acclimated algae or enhanced localized metal complexation. The results imply that redox, acid-base and metal complexation processes in the boundary layer differ from those in bulk water, even under chemically stable bulk conditions, and the boundary layer effect may well be of significance to phytoplankton acquisition of other trace metals.
Assuntos
Cádmio , Chlamydomonas reinhardtii , Disponibilidade Biológica , Metais , FitoplânctonRESUMO
OBJECTIVE: To improve the understanding of chronic pelvic pain (CPP) and to provide evidence-based guidelines of value to primary care health professionals, general obstetricians and gynaecologists, and those who specialize in chronic pain. BURDEN OF SUFFERING: CPP is a common, debilitating condition affecting women. It accounts for substantial personal suffering and health care expenditure for interventions, including multiple consultations and medical and surgical therapies. Because the underlying pathophysiology of this complex condition is poorly understood, these treatments have met with variable success rates. OUTCOMES: Effectiveness of diagnostic and therapeutic options, including assessment of myofascial dysfunction, multidisciplinary care, a rehabilitation model that emphasizes achieving higher function with some pain rather than a cure, and appropriate use of opiates for the chronic pain state. EVIDENCE: Medline and the Cochrane Database from 1982 to 2004 were searched for articles in English on subjects related to CPP, including acute care management, myofascial dysfunction, and medical and surgical therapeutic options. The committee reviewed the literature and available data from a needs assessment of subjects with CPP, using a consensus approach to develop recommendations. VALUES: The quality of the evidence was rated using the criteria described in the Report of the Canadian Task Force on the Periodic Health Examination. Recommendations for practice were ranked according to the method described in that report (Table 1). RECOMMENDATIONS: The recommendations are directed to the following areas: (a) an understanding of the needs of women with CPP; (b) general clinical assessment; (c) practical assessment of pain levels; (d) myofascial pain; (e) medications and surgical procedures; (d) principles of opiate management; (f) increased use of magnetic resonance imaging (MRI); (g) documentation of the surgically observed extent of disease; (h) alternative therapies; (i) access to multidisciplinary care models that have components of physical therapy (such as exercise and posture) and psychology (such as cognitive-behavioural therapy), along with other medical disciplines, such as gynaecology and anesthesia; G) increased attention to CPP in the training of health care professionals; and (k) increased attention to CPP in formal, high-calibre research. The committee recommends that provincial ministries of health pursue the creation of multidisciplinary teams to manage the condition.
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Dor Crônica , Dor Pélvica , Adulto , Idoso , Canadá , Dor Crônica/diagnóstico , Dor Crônica/etiologia , Dor Crônica/fisiopatologia , Dor Crônica/terapia , Feminino , Doenças dos Genitais Femininos/complicações , Ginecologia/organização & administração , Humanos , Pessoa de Meia-Idade , Obstetrícia/organização & administração , Dor Pélvica/diagnóstico , Dor Pélvica/etiologia , Dor Pélvica/fisiopatologia , Dor Pélvica/terapia , Adulto JovemRESUMO
OBJECTIF: Améliorer La compréhension de la douleur pelvienne chronique (DPC) et fournir des directives cliniques factuelles qui bénéficieront aux fournisseurs de soins de santé primaires, aux obstétriciens-gynécologues et aux spécialistes de la douleur chronique. FARDEAU DE LA SOUFFRANCE: La DPC est une pathologie débilitante courante qui affecte les femmes. Elle est à l'origine d'importantes souffrances personnelles et de dépenses de santé considérables associées aux interventions, dont de multiples consultations et un grand nombre de traitements médicaux et chirurgicaux. Puisque la pathophysiologie sous-jacente de cet état pathologique complexe est mal comprise, ces traitements n'ont obtenu que des taux de réussite variables. ISSUES: Efficacité des options diagnostiques et thérapeutiques (y compris l'évaluation du dysfonctionnement myofascial); soins multidisciplinaires; un modèle de réadaptation mettant l'accent sur l'obtention d'un fonctionnement supérieur malgré la présence d'une certaine douleur (plutôt que de chercher à obtenir une guérison totale); et utilisation appropriée des opiacés pour le soulagement de la douleur chronique. PREUVES: Des recherches ont été menées dans Medline et la base de données Cochrane en vue d'en tirer les articles de langue anglaise, publiés entre 1982 et 2004, portant sur des sujets liés à la DPC, dont la gestion des soins actifs, le dysfonctionnement myofascial et les options thérapeutiques médicales et chirurgicales. Les membres du comité ont analysé la littérature pertinente, ainsi que les données disponibles tirées d'une évaluation des besoins des personnes présentant une DPC; ils ont fait appel à une approche de consensus pour l'élaboration des recommandations. VALEURS: La qualité des résultats a été évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur l'examen médical périodique. Les recommandations visant la pratique ont été classées conformément à la méthode décrite dans ce rapport (Tableau 1). RECOMMANDATIONS: Les recommandations visent ce qui suit : (a) compréhension des besoins des femmes présentant une DPC ; (b) évaluation clinique générale ; (c) évaluation pratique des niveaux de douleur ; (d) douleur myofasciale ; (e) médicaments et interventions chirurgicales ; (f) principes de la gestion des opiacés; (g) utilisation accrue de l'imagerie par résonance magnétique (IRM) ; (h) documentation de l'étendue de La maladie constatée au moyen de la chirurgie ; (i) thérapies non conventionnelles; (j) accès à des modèles de soins multidisciplinaires faisant appel à des composantes de physiothérapie (comme l'exercice et la posture) et de psychologie (comme La thérapie cognitivo- comportementale), conjointement avec d'autres disciplines médicales, telles que La gynécologie et l'anesthésie ; (k) attention accrue portée à La DPC dans La formation des professionnels de La sante ; et (l) attention accrue portée à la DPC dans le domaine des recherches officielles et de haut calibre. Le comité recommande que les ministères provinciaux de La Sante prennent des mesures en faveur de la création d'équipes multidisciplinaires pouvant assurer La prise en charge de cette pathologie. Chapitre 2 : Portee et definition de La douleur pelvienne chronique Chapitre 3 : Anamnese, examen physique et évaluation psychologique Chapitre 4 : Explorations Chapitre 5 : Sources de douleur pelvienne chronique Chapitre 6 : Causes urologiques et gastro-intestinales de La douleur pelvienne chronique Chapitre 7 : Dysfonctionnement myofasclal Chapitre 8 : Therapie medicale - résultats en matiere d'efficacite Chapitre 9 : Chirurgie - résultats en matiere d'efficacite Chapitre 11 : Prise en charge multidisciplinaire de La douleur chronique Chapitre 14 : Orientations futures.
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The impact of cadmium on the diatom Nitzschia palea (Kützing) W. Smith 1856 was studied by examining the relation between valve deformities and response through biological processes and genetic expression. Cultures of N. palea were exposed to two Cd treatments (C1 = 2.4 ± 0.6 and C2 = 42.6 ± 4.2 µg Cd/L) along with a control (C0 = 0 µg Cd/L) for 28 days. Cadmium bioaccumulation, diatoms growth, photosynthetic efficiencies, valve deformities and genetic expression were investigated during the course of the experiment. Cadmium exposure had significant effects on bioaccumulation, growth, valve deformities and genetic expression. Maximal effects for all studied endpoints were recorded after 7 days of exposure for the C2 treatment, which corresponded to the sampling time and condition with maximum cadmium bioaccumulation. Abnormal raphe formations (deviation from its lateral position) were significantly more abundant in the C2 treatment compared to the control. Molecular responses were related to cadmium level based on the number of genes impacted, intensity of the response and the frequency of observations. The expression of genes involved in the regulation of mitochondrial metabolism, photosynthesis, oxidative stress and silica metabolism was affected by cadmium exposure.
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Proteínas de Algas/genética , Cádmio/toxicidade , Diatomáceas/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Proteínas de Algas/metabolismo , Diatomáceas/citologia , Diatomáceas/crescimento & desenvolvimento , Diatomáceas/fisiologia , Relação Dose-Resposta a DrogaRESUMO
Silver nanoparticles, used mainly for their antibacterial properties, are among the most common manufactured nanomaterials. How they interact with aquatic organisms, especially how they cross biological membranes, remains uncertain. Free Ag+ ions, released from these nanoparticles, are known to play an important role in their overall bioavailability. In this project, we have studied the uptake of dissolved and nanoparticulate silver by liposomes. These unilamellar vesicles, composed of phospholipids, have long been used as models for natural biological membranes, notably to study the potential uptake of solutes by passive diffusion through the phospholipid bilayer. The liposomes were synthesized using extrusion techniques and were exposed over time to dissolved silver under different conditions where Ag+, AgS2O3-, or AgCl0 were the dominant species. Similar experiments were conducted with the complexes HgCl 2 0 and Cd(DDC) 2 0 , both of which are hydrophobic and known to diffuse passively through biological membranes. The uptake kinetics of Ag+, HgCl 2 0 , and Cd(DDC) 2 0 show no increase in internalized concentrations over time, unlike AgS2O3- and AgCl0, which appear to pass through the phospholipid bilayer. These results are in contradiction with our initial hypothesis that lipophilic Hg and Cd complexes would be able to cross the membrane, whereas silver would not. Encapsulated tritiated water inside the liposomes was shown to rapidly diffuse through the lipid bilayer, suggesting a high permeability. We hypothesize that monovalent anions or complexes as well as small neutral complexes with a strong dipole can diffuse through our model membrane. Finally, liposomes were exposed to 5-nm polyvinylpyrrolidone-coated silver nanoparticles over time. No significant uptake of nanoparticulate silver was observed. Neither disruption of the membrane nor invagination of nanoparticles into the liposomes was observed. This suggests that the main risk caused by AgNPs for nonendocytotic biological cells would be the elevation of the free silver concentration near the membrane surface due to adsorption of AgNPs and subsequent oxidation/dissolution.
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Bicamadas Lipídicas/química , Lipossomos/química , Nanopartículas Metálicas/química , Prata/química , Prata/farmacocinética , Adsorção , Organismos Aquáticos , Disponibilidade Biológica , Cátions/química , Difusão , Bicamadas Lipídicas/farmacocinética , Compostos de Mercúrio/química , Compostos de Mercúrio/farmacocinética , Fosfolipídeos/química , Poluentes Químicos da Água/químicaRESUMO
STUDY OBJECTIVE: To assess the safety and effectiveness of the Minerva Endometrial Ablation System for the treatment of heavy menstrual bleeding in premenopausal women. DESIGN: Multicenter, randomized, controlled, international study (Canadian Task Force classification I). SETTING: Thirteen academic and private medical centers. PATIENTS: Premenopausal women (n = 153) suffering from heavy menstrual bleeding (PALM-COEIN: E, O). INTERVENTION: Patients were treated using the Minerva Endometrial Ablation System or rollerball ablation. MEASUREMENTS AND MAIN RESULTS: At 1-year post-treatment, study success (alkaline hematin ≤80 mL) was observed in 93.1% of Minerva subjects and 80.4% of rollerball subjects with amenorrhea reported by 71.6% and 49% of subjects, respectively. The mean procedure times were 3.1 minutes for Minerva and 17.2 minutes for rollerball. There were no intraoperative adverse events and/or complications reported. CONCLUSION: The results of this multicenter randomized controlled trial demonstrate that at the 12-month follow-up, the Minerva procedure produces statistically significantly higher rates of success, amenorrhea, and patient satisfaction as well as a shorter procedure time when compared with the historic criterion standard of rollerball ablation. Safety results were excellent and similar for both procedures.
Assuntos
Técnicas de Ablação Endometrial/efeitos adversos , Técnicas de Ablação Endometrial/métodos , Menorragia/cirurgia , Adulto , Feminino , Seguimentos , Humanos , Histeroscopia/efeitos adversos , Histeroscopia/métodos , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Minimamente Invasivos/efeitos adversos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Satisfação do Paciente , Pré-Menopausa , Resultado do Tratamento , Estados Unidos , United States Food and Drug AdministrationRESUMO
AIM: To explore the characteristics that influence project management offices acceptance and adoption in healthcare sector. BACKGROUND: The creation of project management offices has been suggested as a promising avenue to promote successful organisational change and facilitate evidence-based practice. However, little is known about the characteristics that promote their initial adoption and acceptance in health care sector. This knowledge is important in the context where many organisations are considering implementing project management offices with nurse managers as leaders. METHODS: A descriptive multiple case study design was used. The unit of analysis was the project management offices. The study was conducted in three university-affiliated teaching hospitals in 2013-14 (Canada). Individual interviews (n = 34) were conducted with senior managers. RESULTS: Results reveal that project management offices dedicated to project and change management constitute an innovation and an added value that addresses tangible needs in the field. CONCLUSION: Project management offices are an innovation highly compatible with health care managers and their approach has parallels to the process of clinical problem solving and reasoning well-known to adopters. IMPLICATIONS FOR NURSING MANAGEMENT: This knowledge is important in a context where many nurses hold various roles in project management offices, such as Director, project manager, clinical expert and knowledge broker.
Assuntos
Equipes de Administração Institucional/tendências , Inovação Organizacional , Canadá , Humanos , Equipes de Administração Institucional/normasRESUMO
Metal toxicity toward microorganisms is usually evaluated by determining growth inhibition. To achieve a mechanistic interpretation of such toxic effects, the intricate coupling between cell growth kinetics and metal partitioning dynamics at the cell-solution interface over time must be considered on a quantitative level. A formalism is elaborated to evaluate cell-surface-bound, internalized, and extracellular metal fractions in the limit where metal uptake kinetics is controlled by internalization under noncomplexing medium conditions. Cell growth kinetics is tackled using the continuous logistic equation modified to include growth inhibition by metal accumulation to intracellular or cell surface sites. The theory further includes metal-proton competition for adsorption at cell-surface binding sites, as well as possible variation of cell size during exposure to metal ions. The formalism elucidates the dramatic impacts of initial cell concentration on metal bioavailability and toxicity over time, in agreement with reported algae bioassays. It further highlights that appropriate definition of toxicity endpoints requires careful inspection of the ratio between exposure time scale and time scale of metal depletion from bulk solution. The latter depends on metal internalization-excretion rate constants, microorganism growth, and the extent of metal adsorption on nonspecific, transporter, and growth inhibitory sites. As an application of the theory, Cd toxicity in the algae Pseudokirchneriella subcapitata is interpreted from constrained modeling of cell growth kinetics and of interfacial Cd-partitioning dynamics measured under various exposure conditions.
Assuntos
Clorófitas/efeitos dos fármacos , Metais/química , Metais/toxicidade , Adsorção , Sítios de Ligação , Cádmio/química , Cádmio/farmacocinética , Cádmio/toxicidade , Clorófitas/crescimento & desenvolvimento , Clorófitas/metabolismo , Ecotoxicologia/métodos , Íons , Cinética , Metais/farmacocinética , Modelos Teóricos , SoluçõesRESUMO
STUDY OBJECTIVE: To assess the safety and effectiveness of the Minerva endometrial ablation system for treating excessive uterine bleeding in premenopausal women. DESIGN: Multicenter, single-arm, objective performance criteria (OPC)-controlled international study (Canadian Task Force classification II-1). SETTING: Seven academic medical centers. PATIENTS: 105 premenopausal women symptomatic for menorrhagia secondary to dysfunctional uterine bleeding. INTERVENTION: Patients were treated using the Minerva endometrial ablation system. MEASUREMENTS AND MAIN RESULTS: Study success, based on a pictorial blood loss assessment chart (PBLAC) score ≤75, was observed in 96.2% of the patients at 1 year posttreatment. Some 69.5% of the patients experienced amenorrhea (PBLAC score 0). The mean duration of the procedure was 3.9 minutes. General anesthesia was used in 9% of cases, with the balance being performed under local and/or intravenous or spinal anesthesia regimens. No intraoperative adverse events and/or complications were reported. No patient required hysterectomy or any additional medical and/or surgical interventions to control bleeding during 1 year of follow-up. Efficacy (success) results were compared between the Minerva system and the OPC, which served as a statistical control. The OPC comprised the US Food and Drug Administration's (FDA) reported success rates of all FDA-approved endometrial ablation systems. The Minerva system had a statistically significantly superior success rate compared with the OPC control. CONCLUSION: The Minerva system was found to be safe and effective for treating patients suffering from menorrhagia. The procedure is quick and effective, does not require endometrial pretreatment, and precludes the need for additional surgical interventions to manage menorrhagia.