Direct Stimulation Of Human Fibroblasts By nCeO2 In Vitro Is Attenuated With An Amorphous Silica Coating

Background: Nano-scaled cerium oxide (nCeO2) is used in a variety of applications, including use as a fuel additive, catalyst, and polishing agent, yet potential adverse health effects associated with nCeO2 exposure remain incompletely understood. Given the increasing utility and demand for engineered nanomaterials (ENMs) such as nCeO2, “safety-bydesign” approaches are currently being sought, meaning that the physicochemical properties (e.g., size and surface chemistry) of the ENMs are altered in an effort to maximize functionality while minimizing potential toxicity. In vivo studies have shown in a rat model that inhaled nCeO2 deposited deep in the lung and induced fibrosis. However, little is known about how the physicochemical properties of nCeO2, or the coating of the particles with a material such as amorphous silica (aSiO2), may affect the bio-activity of these particles. Thus, we hypothesized that the physicochemical properties of nCeO2 may explain its potential to induce fibrogenesis, and that a nano-thin aSiO2 coating on nCeO2 may counteract that effect. Results: Primary normal human lung fibroblasts were treated at occupationally relevant doses with nCeO2 that was either left uncoated or was coated with aSiO2 (amsCeO2). Subsequently, fibroblasts were analyzed for known hallmarks of fibrogenesis, including cell proliferation and collagen production, as well as the formation of fibroblastic nodules. The results of this study are consistent with this hypothesis, as we found that nCeO2 directly induced significant production of collagen I and increased cell proliferation in vitro, while amsCeO2 did not. Furthermore, treatment of fibroblasts with nCeO2, but not amsCeO2, significantly induced the formation of fibroblastic nodules, a clear indicator of fibrogenicity. Such in vitro data is consistent with recent in vivo observations using the same nCeO2 nanoparticles and relevant doses. This effect appeared to be mediated through TGFβ signaling since chemical inhibition of the TGFβ receptor abolished these responses. Conclusions: These results indicate that differences in the physicochemical properties of nCeO2 may alter the fibrogenicity of this material, thus highlighting the potential benefits of “safety-by-design” strategies. In addition, this study provides an efficient in vitro method for testing the fibrogenicity of ENMs that strongly correlates with in vivo finding

Glaucomatous Optic Neuropathy Associated with Nocturnal Dip in Blood Pressure: Findings from the Maracaibo Aging Study

Purpose—To determine which nocturnal blood pressure (BP) parameters (low levels or extreme dipper status) are associated with an increased risk of glaucomatous damage in Hispanics. Design—Observational cross-sectional study. Participants—A subset (n=93) of the participants from the Maracaibo Aging Study (MAS) who met the study eligibility criteria were included. These participants — who were at least 40 years of age — had measurements for optical tomography coherence, visual field tests, 24-hour BP, office BP, and intraocular pressureHg. Methods—Univariate and multivariate logistic regression analyses under the generalized estimating equations (GEE) framework were used to examine the relationships between glaucomatous damage and BP parameters, with particular attention to drops in nocturnal BP. Main Outcome Measures—Glaucomatous optic neuropathy (GON) based on the presence of optic nerve damage and visual field defects. Results—The mean age was 61.9 years, and 87.1% were women. Of 185 eyes evaluated, 50 (27.0%) had signs of GON. Individuals with GON had significantly lower 24-hour and nighttime diastolic BP levels than those without. However, results of the multivariate GEE models indicated that the glaucomatous damage was not related to the average systolic or diastolic BP levels measured over 24 hours, daytime, or nighttime. In contrast, extreme drops in nighttime systolic and diastolic BP (\u3e20% compared with daytime BP) were significant risk factors for glaucomatous damage (odds ratio=19.78 and 5.55, respectively). Conclusions—In this population, the link between nocturnal BP and GON is determined by extreme dipping effects rather than low nocturnal BP levels alone. Further studies considering extreme drops in nocturnal BP in individuals at high risk of glaucoma are warranted

Neuropsychiatric Symptoms Among Hispanics: Results of the Maracaibo Aging Study

Background: Neuropsychiatric symptoms play an important role in diagnosing and clinical follow-up of cognitive impairment and dementia. Objective: We investigated the relationship between neuropsychiatric symptoms, cognitive impairment, and dementia in Hispanics. Methods: We included 529 participants (age ≥40 years) from the Maracaibo Aging Study with standardized neuropsychiatric assessments, including the Neuropsychiatric Inventory (NPI). Based on the Clinical Dementia Rating and the Mini-Mental State Examination scores, participants’ cognitive status was categorized into normal cognition, mild/moderate, and severe cognitive impairment. Diagnosis of dementia was established in a consensus conference. Statistical analyses included multivariable logistic regression models and area under the curve (AUC). Results: The mean age of participants was 59.3 years, and 71.8% were women. The proportion of dementia was 6.8%. Disturbed sleep, anxiety, and depression were the most common neuropsychiatric symptoms in the study sample. In crude analyses, the proportions of hallucinations, aberrant motor behavior, agitation/aggression, apathy, delusions, irritability, eating disturbance, depression, and euphoria were differently distributed among cognitive status groups (p \u3c 0.05). After accounting for confounders, aberrant motor behavior and agitation/aggression remained significantly associated with cognitive impairment and dementia (p \u3c 0.05). The inclusion of the NPI domains significantly improved the AUC to discriminate severe cognitive impairment and dementia above of a basic model that included sex, age, education, alcohol, obesity, serum glucose, total cholesterol, hypertension, and stroke. Conclusion: Neuropsychiatric symptoms are associated with severe cognitive impairment and dementia. The addition of NPI items to the global cognitive assessment might help early detection of dementia in primary care settings

Research on aging during the Venezuelan humanitarian crisis: the experience of the Maracaibo aging study

Background Venezuela is in the throes of a complex humanitarian crisis that is one of the worst in decades to impact any country outside of wartime. This case analysis describes the challenges faced by the ongoing Maracaibo Aging Study (MAS) during the deteriorating conditions in Venezuela. When the MAS began in 1997, it focused on memory-related disorders. Since then, strategic planning and proactive community participation allowed us to anticipate and address logistical, funding, and ethical challenges, and facilitated the enrollment and retention of more than 2500 subjects over 55 years of age. All participants, who are residents of the city of Maracaibo, Venezuela, underwent various assessments on several occasions. Here, we discuss how our approach to implementing a longitudinal, population-based study of age-related conditions has allowed our research program to continue throughout this period of political, economic, and social upheaval. Discussion As the social context in Venezuela became more complicated, new challenges emerged, and strategies to sustain the study and participation were refined. We identified five main mechanisms through which the evolving humanitarian crisis has affected implementation of the MAS: 1) community dynamics; 2) morale of researchers, staff, and participants; 3) financial feasibility; 4) components of the research process; and 5) impact on the health of staff, participants, and their families. Strategies to compensate for the impact on these components were implemented, based on inputs from community members and staff. Improved communication, greater involvement of stakeholders, broadening the scope of the project, and strengthening international collaboration have been the most useful strategies. Particular demands emerged, related to the increased mortality and comorbidities of participants and staff, and deterioration of basic services and safety. Conclusion Although the MAS has faced numerous obstacles, it has been possible to continue a longitudinal research project throughout the humanitarian crisis, because our research team has engaged the community deeply and developed a sense of mutual commitment, and also because our project has provided funding to help keep researchers employed, somewhat attenuating the brain drain

Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin

Background: In inland water systems, it is important to characterize the trophic links in order to identify the ‘trophic species’ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours. Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs. Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentin

Nociones generales de muestreo aplicadas a las ciencias de la salud

El artículo tiene por objetivo describir nociones generales demuestreo aplicadas a las ciencias en el área de la salud, analizandodefiniciones, fórmulas, procedimientos y datos. Enestudios probabilísticos, la población objeto de estudio estádeterminada por la muestra a través de un plan de muestreo.En un proceso estadístico son importantes las unidades primarias,secundarias y terciarias de muestreo. Igualmente, eltipo de muestreo puede ser aleatorio simple, sistemático estratificadoo por conglomerados. Los siguientes criterios requierenclaridad y fundamentación: tamaño de la población,nivel de confianza, error relativo, efecto del diseño, efecto deldiseño ajustado, parámetro de interés, varianza estimada ytasa de no respuesta, permitiendo disminuir costos y tiempo,además de inducir resultados y hallazgos desde la muestraen función de la población. Para analizar un estadístico oparámetro desde un resultado inferencial, se requiere de unexperto en matemáticas o estadística, con conocimiento entécnicas para recolectar, analizar e interpretar la información,razones que permiten al investigador una mayor validez yconfiabilidad de los resultados obtenidos de la investigación