Increased cerebrospinal fluid corticotropin-releasing factor concentrations during tryptophan depletion in healthy adults.

BACKGROUND: Brain serotonin neurotransmission and hypothalamic-pituitary-adrenal axis function are implicated in the pathophysiology of depression, and these systems interact in a reciprocal modulatory fashion. This study examined the effect of tryptophan depletion, which acutely reduces brain serotonin concentrations, on serial cerebrospinal fluid concentrations of corticotropin-releasing factor in healthy humans. METHODS: Five subjects completed a standard tryptophan depletion protocol, and four subjects participated in a comparison condition. Subjects underwent continuous sampling of cerebrospinal fluid via lumbar peristaltic pump. Concentrations of cerebrospinal fluid corticotropin-releasing factor were measured by radioimmunoassay. RESULTS: No mood changes were observed in either group. Tryptophan-depleted subjects exhibited significantly greater increases in corticotropin-releasing factor concentrations over time than subjects in the comparison condition. CONCLUSIONS: These findings highlight the potential importance of corticotropin-releasing factor and serotonin interactions and suggest that activation of corticotropin-releasing-factor-containing neurons could play a role in the emergence of mood symptoms following tryptophan depletion in vulnerable individuals.     

Intérêt du Geriatric Nutritional Risk Index dans la prédiction de mortalité chez les patients hémodialysés : étude préliminaire

IntroductionGeriatric Nutritional Risk Index (GNRI) is a simple and quantitative method (based on three objective measurements: weight, height, albumin) for screening patients at risk for malnutrition. However no data are available regarding its relation with mortality in Caucasian hemodialysis patients. We tested the predictive value of GNRI on mortality in a hemodialysis population followed up prospectively for 18 months.MethodsA total of 46 stable prevalent (mean age: 76 ± 11 years, range: 42–95) hemodialysis patients from one center were included in the study. GNRI with other nutritional parameters were evaluated for all patients.ResultsSixteen patients (35%) died during the 18 months of follow-up. Multiple logistic model showed that GNRI and Charlson co-morbidity score were significant predictors of mortality. Age and gender were not significant.ConclusionOur preliminary study carried out on a series of prevalent hemodialysis patients suggests that GNRI is predictor of mortality. To recommend the use of this index for the screening of hemodialysis patients with malnutrition at risk of mortality, our results should be confirmed by a large cohort study.     

Nurses Share Real‐Life Research Experiences

Nursing for Women's Health convened a group of nurse researchers for a roundtable discussion about the relationship of research to the profession of nursing, how research drives evidence‐based practice and how nurses can get involved in research and in its application to the care of women and newborns.     

Association of Long-Term Diet Quality with Hippocampal Volume: Longitudinal Cohort Study

BACKGROUND

Diet quality is associated with brain aging outcomes. However, few studies have explored in humans the brain structures potentially affected by long-term diet quality. We examined whether cumulative average of the Alternative Healthy Eating Index 2010 (AHEI-2010) score during adult life (an 11-year exposure period) is associated with hippocampal volume.

In vitro immunotoxicology of quantum dots and comparison with dissolved cadmium and tellurium

The increasing use of products derived from nanotechnology has raised concerns about their potential toxicity, especially at the immunocompetence level in organisms. This study compared the immunotoxicity of cadmium sulfate/cadmium telluride (CdS/Cd‐Te) mixture quantum dots (QDs) and their dissolved components, cadmium chloride (CdCl₂)/sodium telluride (NaTeO₃) salts, and a CdCl₂/NaTeO₃ mixture on four animal models commonly used in risk assessment studies: one bivalve (Mytilus edulis), one fish (Oncorhynchus mykiss), and two mammals (mice and humans). Our results of viability and phagocytosis biomarkers revealed that QDs were more toxic than dissolved metals for blue mussels. For other species, dissolved metals (Cd, Te, and Cd‐Te mixture) were more toxic than the nanoparticles (NPs). The most sensitive species toward QDs, according to innate immune cells, was humans (inhibitory concentration [IC₅₀] = 217 μg/mL). However, for adaptative immunity, lymphoblastic transformation in mice was decreased for small QD concentrations (EC₅₀ = 4 μg/mL), and was more sensitive than other model species tested. Discriminant function analysis revealed that blue mussel hemocytes were able to discriminate the toxicity of QDs, Cd, Te, and Cd‐Te mixture (Partial Wilk's λ = 0.021 and p < 0.0001). For rainbow trout and human cells, the immunotoxic effects of QDs were similar to those obtained with the dissolved fraction of Cd and Te mixture. For mice, the toxicity of QDs markedly differed from those observed with Cd, Te, and dissolved Cd‐Te mixture. The results also suggest that aquatic species responded more differently than vertebrates to these compounds. The results lead to the recommendation that mussels and mice were most able to discriminate the effects of Cd‐based NPs from the effects of dissolved Cd and Te at the immunocompetence level. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 9–25, 2015.