A Weight of Evidence approach to support the assessment of the quality of Manila clam farming sites in a coastal lagoon.

Aquaculture productivity in coastal lagoons is endangered by a complex interplay of anthropogenic and environmental factors, amplified by the effects of climate change in these sensitive areas. To reach a more comprehensive assessment of farming sites quality, a quantitative Weight of Evidence approach (QWoE) is applied for the first time to data collected at four Manila clam (R. philippinarum) farming sites in the Venice lagoon (Italy). This included sediment quality, chemical bioaccumulation, and biological responses. Results revealed a greater hazard for sites closer to the open sea. In these areas, the combination of sediment characteristics and a higher frequency of salinity and temperature stress could explain the alterations measured at a transcriptional and biomarker level. The findings demonstrate that a QWoE approach that integrates multiple sources of evidence should also include physicochemical conditions in order to better understand the impacts of human activities and other stressors on clam aquaculture productivity.

Thoracic fluid content by electric bioimpedance correlates with respiratory distress in newborns.

OBJECTIVE: The objective of the study was to compare thoracic fluid content (TFC) between newborn infants with and without respiratory distress. We tested the hypothesis that TFC would be higher in infants with respiratory distress. STUDY DESIGN: A total of 96 newborn infants, gestational age 37.9 (2.6) weeks, were enrolled at birth. TFC by electrical bioimpedance was recorded within 3 h after birth (TFC1) and at 24 h of life (TFC2). RESULTS: TFC1 was higher in infants with respiratory distress at birth (76.8 (24.9) versus 61.6 (16.1) 1 KOhm-1, P<0.0005). The association was independent from gestational age and mode of delivery. TFC2 was independently associated with respiratory distress at 24 h of life (adjusted coefficient b=0.5 (s.d. 0.02), P=0.02). CONCLUSION: TFC by electric bioimpedance independently correlated with the presence of respiratory distress at birth and at 24 h of life in late preterm and term newborn infants.

The care center influences the management of lymphoma patients in a universal health care system: an observational cohort study.

BACKGROUND: Healthcare providers-related disparities in adherence to the treatment plan among lymphoma patients are found even in a universal healthcare system, but the mechanism remains unclear. We investigated the association between the type of care center and the relative dose intensity and determined whether it persists after adjustment for patients' recruitment differences. METHODS: Prospective observational cohort study of 294 patients treated with standard protocols for diffuse large B-cell lymphoma (DLBCL) in teaching or community public hospitals or in private centers in the French Midi-Pyrénées region from 2006-2013. To test our assumptions, we used multinomial and mixed-effect logistic models progressively adjusted for patients' biomedical characteristics, socio-spatial characteristics and treatment-related toxicity events. RESULTS: Patients treated using standard protocols in the teaching hospital had more advanced stage and poorer initial prognosis without limitation regarding the distance from the residence to the care center. Patients' recruitment profile across the different types of care center failed to explain the difference in relative dose intensity. Low relative dose intensity was less often observed in teaching hospital than elsewhere. CONCLUSION: We showed that even in a universal healthcare system, disparities in the management of DLBCL patients' do exist according to the types of care center. A main issue may be to find and diffuse the reasons of this benefit in cancer management in the teaching hospital to the other centers.

Study on the toxicity of phenolic and phenoxy herbicides using the submitochondrial particle assay.

A simple and rapid in vitro toxicological assay, utilizing submitochondrial particles (SMP), has been used to evaluate the toxic effects of fifteen herbicides belonging to the phenol and phenoxyalkanoic acid chemical classes. The SMP assay allows the quantitative evaluation of the toxicity of compounds with different mechanisms of action: uncouplers, inhibitors of the enzyme complexes involved in reverse electron transfer and in oxidative phosphorylation and chemicals that alter the membrane structure. The two groups of herbicides showed different levels of toxicity. For phenol derivatives, EC50 values ranged from 0.16 microM (ioxynil) to 6.7 microM (2,4-dinitrophenol), whereas for phenoxy herbicides EC50 values ranged from 21 microM (2,4,5-trichlorophenoxyacetic acid, 2,4,5-T) to 110 microM (4-chloro-2-methylphenoxyacetic acid, MCPA). On the average, the toxicity of phenolic compounds is greater than that of phenoxyalkanoic acids by two orders of magnitude. Quantitative structure-activity relationships (QSAR) were developed between EC50 values and various molecular descriptors. The results suggest the existence of different mechanisms of action for the two classes of compounds. The findings obtained for phenolic herbicides are consistent with a protonophoric uncoupling mechanism, whereas for phenoxy herbicides a non-specific mode of action at membrane level can be hypothesized.

Assessment of chloroaniline toxicity by the submitochondrial particle assay.

The effects on mitochondrial respiration of 15 chloroanilines were recorded by using the in vitro response of submitochondrial particles (SMP) from beef heart mitochondria. The bioassay procedure for SMP is based on the process of reverse electron transfer, which can be negatively affected by inhibitors of electron transport, by uncouplers, and by chemicals that impair membrane integrity. The EC50 values, determined for the tested chloroanilines, indicate a general tendency of increasing toxicity with increasing chlorine substitution. In order to validate the results obtained and to evaluate the capability of the SMP assay to reproduce the toxic effects of the examined compounds on different freshwater species, the EC50 values were compared with literature data from other biological assays regarding both in vitro systems and whole organisms. A good correlation was found in particular with two widely used testing systems, the Microtox and the Tetrahymena assays. In addition, quantitative structure-activity relationships (QSARs) were established between the EC50 values and various molecular descriptors for hydrophobic, steric, and electronic interactions. The results obtained were utilized to elucidate the mechanism of toxic action of chloroanilines, which are commonly reported to act by the polar narcosis mode of action. Moreover, they confirmed that the SMP assay can be a useful tool for studying the toxicity of chemicals that act nonspecifically by impairing membrane structure and functions.

Quantitative structure-activity relationships for the toxicity of chlorophenols to mammalian submitochondrial particles.

The toxicity of a series of chlorophenols, determined by a short-term in vitro assay utilizing mammalian submitochondrial particles, was related to the physicochemical and structural properties of these compounds. Quantitative Structure-Activity Relationships were defined by correlating EC50 values with six molecular descriptors, chosen to represent lipophilic, electronic and steric effects: the n-octanol/water partition coefficient (log Kow), the constant of Hammett (sigma sigma), the acid dissociation constant (pKa), the first order valence molecular connectivity index (1 chi v), the perimeter of the efficacious section (sigma D) and the melting point (m.p.). The results of regression analysis showed that log Kow is the most successful descriptor, indicating that the ability of chlorophenols to partition into the lipid bilayer of the mitochondrial membrane has an important role in determining their toxic effects. These results are consistent with a molecular mechanism of uncoupling action based on the chemiosmotic theory and on the protonophoric properties of chlorophenols. The quality of the QSAR models confirms the suitability of the SMP assay as a short-term prediction tool for aquatic toxicity of environmental pollutants acting on respiratory functions.