Effect of hypertonic saline treatment on the inflammatory response after hydrochloric acid-induced lung injury in pigs

OBJECTIVES:

Hypertonic saline has been proposed to modulate the inflammatory cascade in certain experimental conditions, including pulmonary inflammation caused by inhaled gastric contents. The present study aimed to assess the potential anti-inflammatory effects of administering a single intravenous dose of 7.5% hypertonic saline in an experimental model of acute lung injury induced by hydrochloric acid.

METHODS:

Thirty-two pigs were anesthetized and randomly allocated into the following four groups: Sham, which received anesthesia and were observed; HS, which received intravenous 7.5% hypertonic saline solution (4 ml/kg); acute lung injury, which were subjected to acute lung injury with intratracheal hydrochloric acid; and acute lung injury + hypertonic saline, which were subjected to acute lung injury with hydrochloric acid and treated with hypertonic saline. Hemodynamic and ventilatory parameters were recorded over four hours. Subsequently, bronchoalveolar lavage samples were collected at the end of the observation period to measure cytokine levels using an oxidative burst analysis, and lung tissue was collected for a histological analysis.

RESULTS:

Hydrochloric acid instillation caused marked changes in respiratory mechanics as well as blood gas and lung parenchyma parameters. Despite the absence of a significant difference between the acute lung injury and acute lung injury + hypertonic saline groups, the acute lung injury animals presented higher neutrophil and tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-8 levels in the bronchoalveolar lavage analysis. The histopathological analysis revealed pulmonary edema, congestion and alveolar collapse in both groups; however, the differences between groups were not significant. Despite the lower cytokine and neutrophil levels observed in the acute lung injury + hypertonic saline group, significant differences were not observed among the treated and non-treated groups.

CONCLUSIONS:

Hypertonic saline infusion after intratracheal hydrochloric acid instillation does not have an effect on inflammatory biomarkers or respiratory gas exchange.     

The morphological and molecular characterization of Henneguya rotunda n. sp., a parasite of the gill arch and fins of Salminus brasiliensis from the Mogi Guaçu River,Brazil

A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Guaçu River, municipality of Pirassununga, São Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. The mature spores found infecting the fins had oval spore body with 7.1?±?0.2 μm in length, 5.6?±?0.2 μm in width, 3.7?±?0.1 μm in thickness, 16.4?±?1.2 μm in length of the caudal process, and 23.6?±?1.1 μm in total length of the spore. In a frontal view, the polar capsule was observed to be symmetrical with 3.4?±?0.2 μm in length and 1.8?±?0.1 μm in width. Mature spores contain six to seven turns of the polar filaments. The morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. The molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100 % similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis.     

Cadmium toxicity and its relationship with disturbances in the cytoskeleton,cell cycle and chromosome stability

Ecotoxicology - This study aimed to investigate the mode of action of cadmium (Cd) toxicity at cell level, especially at early stages of plant exposure. Tomato seedlings were cultivated in growth...     

From the Cover: Science in support of the Deepwater Horizon response

This introduction to the Special Feature presents the context for science during the Deepwater Horizon oil spill response, summarizes how scientific knowledge was integrated across disciplines and statutory responsibilities, identifies areas where scientific information was accurate and where it was not, and considers lessons learned and recommendations for future research and response. Scientific information was integrated within and across federal and state agencies, with input from nongovernmental scientists, across a diverse portfolio of needs—stopping the flow of oil, estimating the amount of oil, capturing and recovering the oil, tracking and forecasting surface oil, protecting coastal and oceanic wildlife and habitat, managing fisheries, and protecting the safety of seafood. Disciplines involved included atmospheric, oceanographic, biogeochemical, ecological, health, biological, and chemical sciences, physics, geology, and mechanical and chemical engineering. Platforms ranged from satellites and planes to ships, buoys, gliders, and remotely operated vehicles to laboratories and computer simulations. The unprecedented response effort depended directly on intense and extensive scientific and engineering data, information, and advice. Many valuable lessons were learned that should be applied to future events.     

Regulation of RAS oncogenicity by acetylation

Members of the RAS small GTPase family regulate cellular responses to extracellular stimuli by mediating the flux through downstream signal transduction cascades. RAS activity is strongly dependent on its subcellular localization and its nucleotide-binding status, both of which are modulated by posttranslational modification. We have determined that RAS is posttranslationally acetylated on lysine 104. Molecular dynamics simulations suggested that this modification affects the conformational stability of the Switch II domain, which is critical for the ability of RAS to interact with guanine nucleotide exchange factors. Consistent with this model, an acetylation-mimetic mutation in K-RAS4B suppressed guanine nucleotide exchange factor-induced nucleotide exchange and inhibited in vitro transforming activity. These data suggest that lysine acetylation is a negative regulatory modification on RAS. Because mutations in RAS family members are extremely common in cancer, modulation of RAS acetylation may constitute a therapeutic approach.