Inhalation of an Ethanol-Based Zileuton Formulation Provides a Reduction of Pulmonary Adenomas in the A/J Mouse Model

Potential efficacy of zileuton, a 5-LOX inhibitor, was evaluated for the reduction of pulmonary adenomas in the A/J murine model when administered via nose-only inhalation. Development of pulmonary adenomas was induced with benzo(a)pyrene. Animals were treated with a zileuton solution (5 mg/mL in 85:15 ethanol/water) either twice weekly or five times a week via nose-only inhalation; The placebo solution (85:15 EtOH/H₂O, no active) was also evaluated. Dose delivered was calculated to be 1.2 mg/kg per exposure for each zileuton group. After 20 weeks of treatment, surface tumors were enumerated and histologically assessed. A significant reduction in tumor count was noted for both the twice weekly administration (40%) and the five times a week administration (59%). The data also showed a significant reduction for the group, which received the placebo (approximately 58%). The treatment groups were also found to have an impact on the histological stages of adenoma development.     

Na+/K+-ATPase Inhibition Partially Mimics the Ethanol-Induced Increase of the Golgi Cell-Dependent Component of the Tonic GABAergic Current in Rat Cerebellar Granule Cells

Cerebellar granule cells (CGNs) are one of many neurons that express phasic and tonic GABAergic conductances. Although it is well established that Golgi cells (GoCs) mediate phasic GABAergic currents in CGNs, their role in mediating tonic currents in CGNs (CGN-I_tonic) is controversial. Earlier studies suggested that GoCs mediate a component of CGN-I_tonic that is present only in preparations from immature rodents. However, more recent studies have detected a GoC-dependent component of CGN-I_tonic in preparations of mature rodents. In addition, acute exposure to ethanol was shown to potentiate the GoC component of CGN-I_tonic and to induce a parallel increase in spontaneous inhibitory postsynaptic current frequency at CGNs. Here, we tested the hypothesis that these effects of ethanol on GABAergic transmission in CGNs are mediated by inhibition of the Na⁺/K⁺-ATPase. We used whole-cell patch-clamp electrophysiology techniques in cerebellar slices of male rats (postnatal day 23–30). Under these conditions, we reliably detected a GoC-dependent component of CGN-I_tonic that could be blocked with tetrodotoxin. Further analysis revealed a positive correlation between basal sIPSC frequency and the magnitude of the GoC-dependent component of CGN-I_tonic. Inhibition of the Na⁺/K⁺-ATPase with a submaximal concentration of ouabain partially mimicked the ethanol-induced potentiation of both phasic and tonic GABAergic currents in CGNs. Modeling studies suggest that selective inhibition of the Na⁺/K⁺-ATPase in GoCs can, in part, explain these effects of ethanol. These findings establish a novel mechanism of action of ethanol on GABAergic transmission in the central nervous system.     

Genetic Targets of Hydrogen Sulfide in Ventilator-Induced Lung Injury – A Microarray Study

Recently, we have shown that inhalation of hydrogen sulfide (H₂S) protects against ventilator-induced lung injury (VILI). In the present study, we aimed to determine the underlying molecular mechanisms of H₂S-dependent lung protection by analyzing gene expression profiles in mice. C57BL/6 mice were subjected to spontaneous breathing or mechanical ventilation in the absence or presence of H₂S (80 parts per million). Gene expression profiles were determined by microarray, sqRT-PCR and Western Blot analyses. The association of Atf3 in protection against VILI was confirmed with a Vivo-Morpholino knockout model. Mechanical ventilation caused a significant lung inflammation and damage that was prevented in the presence of H₂S. Mechanical ventilation favoured the expression of genes involved in inflammation, leukocyte activation and chemotaxis. In contrast, ventilation with H₂S activated genes involved in extracellular matrix remodelling, angiogenesis, inhibition of apoptosis, and inflammation. Amongst others, H₂S administration induced Atf3, an anti-inflammatory and anti-apoptotic regulator. Morpholino mediated reduction of Atf3 resulted in elevated lung injury despite the presence of H₂S. In conclusion, lung protection by H₂S during mechanical ventilation is associated with down-regulation of genes related to oxidative stress and inflammation and up-regulation of anti-apoptotic and anti-inflammatory genes. Here we show that Atf3 is clearly involved in H₂S mediated protection.     

Exclosure fences around nests of imperiled Florida Grasshopper Sparrows reduce rates of predation by mammals

Increasing nest survival by excluding predators is a goal of many bird conservation programs. However, new exclosure projects should be carefully evaluated to assess the potential risks of disturbance. We tested the effectiveness of predator exclosure fences (hereafter, fences) for nests of critically endangered Florida Grasshopper Sparrows (Ammodramus savannarum floridanus) at a dry prairie site (Three Lakes; 2015–2018) and a pasture site (the Ranch; 2015–2016) in Osceola County, Florida, USA. We installed fences at nests an average of 8 days after the start of incubation, and nest abandonment after fence installation was rare (2 of 149 installations). Predation was the leading cause of failure for unfenced nests at both sites (48–73%). At Three Lakes, nest cameras revealed that mammals and snakes were responsible for 61.5% and 38.5% of predation events, respectively, at unfenced nests. Fences reduced the daily probability of predation (0.016 for fenced nests vs. 0.074 for unfenced nests). The probability that a fenced nest would survive from discovery to fledging was more than double that of unfenced nests (60.4% vs. 27.7%). However, we found no difference in daily nest survival at the Ranch between the year before nests were fenced (2015; 0.874) and the year when all but one nest were fenced (2016; 0.867) because red imported fire ants (Solenopsis invicta) were responsible for 86% of predation events at fenced nests at the Ranch. The use of cameras at fenced nests revealed that site‐specific differences in nest predators explained variation in fence efficiency between sites. Our fence design may be useful for other species of grassland birds, but site‐specific predator communities and species‐specific response of target bird species to fences should be assessed before installing fences at other sites.     

Delivery of Functionality in Complex Food Systems: Physically Inspired Approaches from Nanoscale to Microscale,Wageningen 18–21 October 2009

The Wageningen Delivery of Functionality symposium covered all aspects involved with food structural design to arrive at high-quality foods which meet demanding customer expectations and regulatory requirements. The symposium integrated aspects from the structural organization of foods at molecular and supramolecular scales to dedicated techniques required to describe and visualize such structures, the gastro-intestinal events and how to model these in a laboratory setting, and finally the impact those food structures and ingredients have on the consumer’s physiology and on the human perception. As an interdisciplinary platform, bringing together more than 160 researchers from academia and industry, the symposium meanwhile fulfills an important role in the food science community.     

Spontaneous Aggregation and Cytotoxicity of the β-Amyloid Aβ1–40: A Kinetic Model

The time dependency of the spontaneous aggregation of the fibrillogenic β-Amyloid peptide, Aβ^1–40, was measured by turbidity, circular dichroism, HPLC, and fluorescence polarization. The results by all methods were comparable and they were most consistent with a kinetic model where the peptide first slowly forms an activated monomeric derivative (AM), which is the only species able to initiate, by tetramerization, the formation of linear aggregates. The anti-Aβ antibody 6E10, raised against residues 1–17, at concentrations of 200–300 nM delayed significantly the aggregation of 50 μM amyloid peptide. The anti–Aβ antibody 4G8, raised against residues 17–24, was much less active in that respect, while the antibody A162, raised against the C-terminal residues 39–43 of the full-length Aβ was totally inactive at those concentrations. Concomitant with the aggregation experiments, we also measured the time dependency of the Aβ^1–40–induced toxicity toward SH-EP1 cells and hippocampal neurons, evaluated by SYTOX Green fluorescence, lactate dehydrogenase release, and activation of caspases. The extent of cell damage measured by all methods reached a maximum at the same time and this maximum coincided with that of the concentration of AM. According to the kinetic scheme, the latter is the only transient peptide species whose concentration passes through a maximum. Thus, it appears that the toxic species of Aβ^1–40 is most likely the same transient activated monomer that is responsible for the nucleation of fibril formation. These conclusions should provide a structural basis for understanding the toxicity of Aβ^1–40 in vitro and possibly in vivo.     

THE ZOOSPORE OF CHLOROKYBUS ATMOPHYTICUS,A CHAROPHYTE WITH SARCINOID GROWTH HABIT

Chlorokybus atmophyticus has a sarcinoid growth habit and produces scale-covered zoospores. Flagella are laterally inserted and attached internally to a multilayered structure characteristic of the Charophyceae. There are two kinds of pyrenoid in each cell, a feature previously observed in only one scaly green flagellate. C. atmophyticus demonstrates that the sarcinoid growth habit arose independently at least twice in the green algae and cannot be used to define taxonomic groups unless combined with other criteria. It is further concluded that C. atmophyticus should be classified in a separate family Chlorokybaceae and a separate order Chloroky bales.