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1.
Eur Radiol ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32052172

RESUMO

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.

2.
Environ Pollut ; 258: 113804, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31874439

RESUMO

Our knowledge of the processes leading to the bioaccumulation of rare earth elements (REE) in aquatic biota is limited. As the contamination of freshwater ecosystems by anthropogenic REE have recently been reported, it becomes increasingly urgent to understand how these metals are transferred to freshwater organisms in order to develop appropriate guidelines. We exposed rainbow trout (Oncorhynchus mykiss) to an REE, yttrium (Y), to either a range of Y-contaminated prey (Daphnia magna) or a range of Y-contaminated water. For the feeding experiment, the relationship between the Y assimilation by O. mykiss and the Y subcellular fractionation in D. magna was evaluated. Assimilation efficiency of Y by O. mykiss was low, ranging from 0.8 to 3%. These values were close to the proportion of Y accumulated in D. magna cytosol, 0.6-2%, a theoretical trophically available fraction. Moreover, under our laboratory conditions, water appeared as a poor source of Y transfer to O. mykiss. Regardless of the source of contamination, a similar pattern of Y bioaccumulation among O. mykiss tissues was revealed: muscles < liver < gills < intestine. We conclude that the trophic transfer potential of Y is low and the evaluation of Y burden in prey cytosol appears to be a relevant predictor of Y assimilation by their consumers.

3.
Can J Ophthalmol ; 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31712031

RESUMO

OBJECTIVE: To describe the demographics, clinical presentation, proportion of co-infection with human immunodeficiency virus (HIV), and treatment of patients with ocular syphilis seen at the ophthalmology department of 2 tertiary centres in Montreal, Canada. DESIGN: Retrospective case series. PARTICIPANTS AND METHODS: A total of 169 eyes of 115 patients, seen between 2000 and 2015, with a positive syphilis treponemal serology and a likely syphilis-related ophthalmologic diagnosis. Subgroup analysis was performed between HIV-infected and HIV-uninfected patients. RESULTS: Mean age of onset was 55 years, and 79% were male. Mean presenting logMAR visual acuity was 0.7. HIV status was available for 66%, of whom 49% were HIV-infected. The anatomical ocular diagnoses included isolated anterior uveitis (18%) and posterior segment involvement (42%). Both eyes were affected in 47%. Lumbar puncture (LP) was performed in 55%, of whom 22% had a positive cerebrospinal fluid (CSF) Venereal Disease Research Laboratory (VDRL) test. Antibiotherapy, consisting of intravenous penicillin alone or in addition to intramuscular benzathine penicillin, was administered in 65 patients (69%). Treatment allowed a visual improvement of -0.23 logMAR. HIV-infected patients were younger men (p < 0.01) and had more abnormal CSF analysis (p = 0.02), but there were no statistically significant differences in the anatomical location of ocular inflammation or visual function improvement. CONCLUSIONS: Given its varied presentations, syphilis must always be part of the differential diagnosis of intraocular inflammation. HIV testing and an LP are required in the evaluation of ocular syphilis, which should be treated as neurosyphilis with the appropriate regimen.

4.
ACS Omega ; 4(9): 13747-13755, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31497692

RESUMO

The demand for rare earth elements (REEs) has increased since the 1990s leading to the development of many mining projects worldwide. However, less is known about how organisms can handle these metals in natural aquatic systems. Through laboratory experiments, we assessed the chronic toxicity and subcellular fractionation of yttrium (Y), one of the four most abundant REEs, in three freshwater organisms commonly used in aquatic toxicology: Daphnia magna, Chironomus riparius, and Oncorhynchus mykiss. In bioassays using growth as an end point, C. riparius was the only organism showing toxicity at Y exposure concentrations close to environmental ones. The lowest observable effect concentrations (LOECs) of Y assessed for D. magna and O. mykiss were at least 100 times higher than the Y concentration in natural freshwater. A negative correlation between Y toxicity and water hardness was observed for D. magna. When exposed to their respective estimated LOECs, D. magna bioaccumulated 15-45 times more Y than the other two organisms exposed to their own LOECs. This former species sequestered up to 75% of Y in the NaOH-resistant fraction, a putative metal-detoxified subcellular fraction. To a lesser extent, C. riparius bioaccumulated 20-30% of Y in this detoxified fraction. In contrast, the Y subcellular distribution in O. mykiss liver did not highlight any notable detoxification strategy; Y was accumulated primarily in mitochondria (ca. 32%), a putative metal-sensitive fraction. This fraction was also the main sensitive fraction where Y accumulated in C. riparius and D. magna. Hence, the interaction of Y with mitochondria could explain its toxicity. In conclusion, there is a wide range of subcellular handling strategies for Y, with D. magna accumulating high quantities but sequestering most of it in detoxified fractions, whereas O. mykiss tending to accumulate less Y but in highly sensitive fractions.

5.
Environ Sci Technol ; 53(11): 6539-6545, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31082264

RESUMO

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 , Ferro
6.
Environ Sci Technol ; 53(11): 6511-6519, 2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31074972

RESUMO

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 Mar
7.
Ecotoxicol Environ Saf ; 176: 355-363, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30954621

RESUMO

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/química
8.
Ecotoxicol Environ Saf ; 169: 85-92, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30439583

RESUMO

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 (< 120 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 µM = 0.034 ±â€¯0.013 nmol 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%) > debris (17 ±â€¯4%) > organelles (12 ±â€¯2%) > heat-stable peptides (HSP) (~2%) > heat-denaturable proteins (HDP) (< 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/toxicidade
9.
Transpl Infect Dis ; 21(1): e12999, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30203904

RESUMO

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 Micobactéria não Tuberculosa/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 Micobactéria não Tuberculosa/complicações , Infecções por Micobactéria não Tuberculosa/diagnóstico por imagem , Infecções por Micobactéria não Tuberculosa/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 imagem
10.
J Obstet Gynaecol Can ; 40(11): e747-e787, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30473127

RESUMO

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.


Assuntos
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 Jovem
11.
J Obstet Gynaecol Can ; 40(11): e788-e836, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30473128

RESUMO

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.

12.
PLoS One ; 13(9): e0204001, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30212544

RESUMO

BACKGROUND: Although reverse sequence algorithms (RSA) for syphilis screening are performing well, they still have to rely on treponemal confirmatory tests at least for sera reactive by enzyme immunoassay/chemiluminescence immunoassay (EIA/CIA) and unreactive by rapid plasma reagin (RPR). Quebec's laboratory network previously showed that 3.3% of EIA/CIA reactive and weakly-reactive RPR samples (RPR titer of 1 to 4) would have been misclassified as syphilis cases if a treponemal confirmatory test had not been performed. OBJECTIVES: To correlate the magnitude of signal-to-cutoff (S/CO) ratios of the 4 most used commercial first-line EIA/CIA kits in Quebec with syphilis confirmation results and establish a S/CO value above which treponemal confirmation would not be required. METHODS: Serum samples from previously undiagnosed individuals (n = 7 404) obtained between January 2014 and February 2017 that were reactive by EIA/CIA and either negative by RPR or reactive with a low titer (1 to 4) were included in the study. All samples were tested with Treponema pallidum particle agglutination (TP-PA) and, if negative or inconclusive, with a line immunoassay (LIA). Syphilis infection confirmation was defined by a reactive TP-PA or LIA. Logistic regression analysis was used to determine S/CO values (95% CI lower bound = 0.98) above which confirmation would not be required. The four kits studied were Architect TP, BioPlex IgG, Syphilis EIA II, and Trep-Sure. RESULTS: Of 2609 reactive EIA/CIA specimens tested for the determination of S/CO values, 1730 (66%) were confirmed as true syphilis cases. Confirmation rate was significantly higher in samples with low-titer positive RPR (92%) than with negative RPR samples (54%); p<0.01. A linear probability model (95% CI lower bound = 0.98) predicted the S/CO value above which a confirmation would no longer be needed for the Architect TP (16.4), Bioplex IgG (7.4) and Trep-Sure (24.6). No linearity was observed between the S/CO value of Syphilis EIA II and the confirmation rate. The validity of the predicted S/CO values was investigated using 4 795 specimens. The use of an S/CO value of 16.4 with the Architect TP kit and of 24.6 for the Trep-Sure kit would obviate the need for confirmation of 18.5% and 13.2% of sera from the all RPR subgroup, respectively. For the BioPlex IgG kit, 81.1% of sera would not require confirmation when using the S/CO value of 7.4 in the low titer RPR subgroup. CONCLUSION: Signal-to-cut-off values could be used to identify sera that do not require extra treponemal confirmation for 3 of the 4 most used first-line EIA/CIA kits in Quebec. Using these values in our current reverse screening algorithm (RSA) would avoid the need for confirmatory tests in 14 to 20% of sera, a proportion that could reach 75% among low-titer RPR.


Assuntos
Sorodiagnóstico da Sífilis/métodos , Sífilis/diagnóstico , Algoritmos , Erros de Diagnóstico , Humanos , Técnicas Imunoenzimáticas/métodos , Técnicas Imunoenzimáticas/estatística & dados numéricos , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Quebeque , Razão Sinal-Ruído , Sorodiagnóstico da Sífilis/estatística & dados numéricos , Teste de Imobilização do Treponema/estatística & dados numéricos
13.
Arch Environ Contam Toxicol ; 75(4): 634-646, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30238147

RESUMO

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.


Assuntos
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/química
14.
Environ Sci Technol ; 52(14): 7988-7995, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29883120

RESUMO

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 , Fitoplâncton
15.
Ecotoxicology ; 27(6): 675-688, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29797171

RESUMO

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.


Assuntos
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 Droga
16.
Environ Toxicol Chem ; 37(8): 2112-2122, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29672902

RESUMO

Selenium (Se) concentrations measured in lake planktonic food chains (microplankton <64 µm, copepods, and Chaoborus larvae) were strongly correlated with the concentrations of dissolved organic Se. These correlations were strengthened slightly by adding the concentrations of dissolved selenate to those of organic Se. To better understand the role of Se species and the influence of water chemistry on Se uptake, we exposed the green alga Chlamydomonas reinhardtii to selenite, selenate, or selenomethionine at various H+ ion and sulfate concentrations under controlled laboratory conditions. At low sulfate concentrations, inorganic Se species (selenate >> selenite) were more readily accumulated by this alga than was selenomethionine. However, at higher sulfate concentrations the uptake of selenite was higher than that of selenate, whereas the uptake of selenomethionine remained unchanged. Although the pH of the exposure water did not influence the uptake of selenate by this alga, the accumulation of selenomethionine and selenite increased with pH because of their relative pH-related speciation. The Se concentrations that we measured in C. reinhardtii exposed to selenomethionine were 30 times lower than those that we measured in field-collected microplankton exposed in the same laboratory conditions. This difference is explained by the taxa present in the microplankton samples. Using the present laboratory measurements of Se uptake in microplankton and of natural Se concentrations in lake water allowed us to model Se concentrations in a lake pelagic food chain. Environ Toxicol Chem 2018;37:2112-2122. © 2018 SETAC.


Assuntos
Chlamydomonas reinhardtii/metabolismo , Lagos , Plâncton/metabolismo , Ácido Selênico/análise , Ácido Selenioso/análise , Selênio/análise , Sulfatos/análise , Animais , Dípteros/metabolismo , Cadeia Alimentar , Geografia , Concentração de Íons de Hidrogênio , Larva/metabolismo , Fatores de Tempo
17.
J Nurs Manag ; 25(8): 657-665, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28891171

RESUMO

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/normas
18.
Can J Kidney Health Dis ; 4: 2054358117695792, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28321326

RESUMO

RATIONALE: Kidney transplantation has become standard of care for carefully selected patients living with human immunodeficiency virus (HIV) and end-stage renal disease (ESRD) in the highly active antiretroviral therapy (HAART) era. American and European prospective cohort studies have reported similar patient and graft survival compared with HIV-negative kidney transplant recipients. Despite an increased rate of acute rejection, partially due to drug interactions, HIV immunovirologic parameter generally remains under control during immunosuppression. A few cases of kidney transplantation between HIV-infected patients were done in South Africa and showed favorable results. No cases of kidney transplantation from an HIV-positive donor in Canada have previously been reported. PRESENTING CONCERNS OF THE PATIENT: A 60-year-old Canadian man with HIV infection presented in 2007 with symptoms compatible with acute renal failure secondary to IgA nephropathy. Chronic kidney disease resulted after the acute episode. DIAGNOSES: Hemodialysis was started in 2012. The patient was referred for a kidney transplantation evaluation. INTERVENTIONS: The patient underwent kidney transplantation from an HIV-positive donor in January 2016. The recipient's antiretroviral regimen consisted of abacavir, lamivudine, and dolutegravir. No drug interactions have been reported between these antiretrovirals and the maintenance immunosuppressive regimen used. OUTCOMES: The outcome at 7 months post transplantation was excellent, with good graft function and adequate control of HIV replication, in the absence of opportunistic infections at a time when immunosuppression is at its highest intensity. No acute rejection was reported. An episode of bacteremic graft pyelonephritis due to Enterococcus faecalis was successfully treated after transplantation. NOVEL FINDING: With careful selection of patient, kidney transplantation between HIV-infected patients is a viable option. The use of antiretroviral drugs free of interactions simplified the dosing and management of the immunosuppressive drugs.

19.
J Minim Invasive Gynecol ; 24(1): 124-132, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27687851

RESUMO

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 Administration
20.
Aquat Toxicol ; 182: 49-57, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27866075

RESUMO

Chromium occurs in aquatic environments under two main redox forms, namely Cr(III) and Cr(VI), with different geochemical and biochemical properties. Cr(VI) readily crosses biological membranes of living organisms and once inside the cells it undergoes a rapid reduction to Cr(III). The route of entry for the latter form is, however, poorly known. Using the radioactive tracer 51Cr we compared the accumulation (absorption and adsorption) of the two Cr forms by the green unicellular alga Chlamydomonas reinhardii after 1h and 72h of exposure to 100nM of either Cr(III) or Cr(VI) at pH 7. Both Cr forms had similar accumulation, with a major part in the extracellular (adsorbed) fraction after 1h and a major part of total accumulated Cr in the intracellular (absorbed) fraction after 72h. We also investigated the intracellular partitioning of Cr using an operational fractionation scheme and found that both Cr forms had similar distributions among fractions: Cr was mostly associated with organelles (23±12% after 1h and 37±7% after 72h) and cytosolic heat-stable proteins and peptides (39±18% after 1h and 35±3% after 72h) fractions. Further investigations using a metallomic approach (SEC-ICP-MS) were performed with the heat-stable proteins and peptides fraction to compare the distribution of the two Cr forms among various biomolecules of this fraction. One Cr-binding biomolecule (∼28kDa) appeared after 1h of exposure for both Cr species. After 72h another biomolecule of lower molecular weight (∼0.7kDa) was involved in binding Cr and higher signal intensities were observed for Cr(VI) than for Cr(III). We show, for the first time, that both Cr(III) and Cr(VI) have similar fate within algal cells, supporting the tenet that a unique redox form occurs within cells.


Assuntos
Chlamydomonas reinhardtii/metabolismo , Cromo/metabolismo , Cromo/química , Exposição Ambiental , Água Doce/química , Oxirredução , Poluentes Químicos da Água/metabolismo
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