Ethanol potentiates the inhibitory effect of D-galactosamine on protein synthesis in isolated hepatocytes

The effect of the combined addition of D-galactosamine and ethanol on hepatic protein synthesis was studied in isolated mouse hepatocytes. 2.5 mM D-galactosamine or 40 mM ethanol alone caused slight or no inhibition of amino acid incorporation into proteins. However, a profound inhibition (about 80%) was observed if D-galactosamine of the same dose was added after a preincubation of the cells with 40 mM ethanol and vice versa. It shows that there is a strong mutual potentiation between D-galactosamine and ethanol in the inhibition of protein synthesis.     

Interactions between Bacillus anthracis and Plants May Promote Anthrax Transmission

Environmental reservoirs are essential in the maintenance and transmission of anthrax but are poorly characterized. The anthrax agent, Bacillus anthracis was long considered an obligate pathogen that is dormant and passively transmitted in the environment. However, a growing number of laboratory studies indicate that, like some of its close relatives, B. anthracis has some activity outside of its vertebrate hosts. Here we show in the field that B. anthracis has significant interactions with a grass that could promote anthrax spore transmission to grazing hosts. Using a local, virulent strain of B. anthracis, we performed a field experiment in an enclosure within a grassland savanna. We found that B. anthracis increased the rate of establishment of a native grass (Enneapogon desvauxii) by 50% and that grass seeds exposed to blood reached heights that were 45% taller than controls. Further we detected significant effects of E. desvauxii, B. anthracis, and their interaction on soil bacterial taxa richness and community composition. We did not find any evidence for multiplication or increased longevity of B. anthracis in bulk soil associated with grass compared to controls. Instead interactions between B. anthracis and plants may result in increased host grazing and subsequently increased transmission to hosts.     

Preconditioning with volatile anaesthetic sevoflurane in ischemic retinal lesion in rats

Volatile anaesthetic agents have been recognized for their neuroprotective properties since the 1960s. However, little is known regarding the potential retinoprotective effects of preconditioning by anaesthetic drugs. Retinal ischemia can be modeled by permanent bilateral common carotid artery occlusion (BCCAO). Here we studied the degree of ischemic injury with preconditioning by sevoflurane in the rat retina. During the BCCAO operation and preconditioning Wistar rats were anaesthetized with 1 MAC of sevoflurane. The oxygen, carbon dioxide, and anaesthetic vapor concentration in the anaesthetizing box was monitored with a gas analyzer. We examined 4 groups: non- and preconditioning groups in control and BCCAO animals. The duration of preconditioning period was 1?h and it was performed 1?day before BCCAO. The retinas were processed for histological evaluation after 2?weeks survival to determine the cell number in the ganglion cell layer and the thickness of the whole retina and that of all retinal layers. BCCAO-induced retinal ischemic injury was ameliorated by sevoflurane preconditioning. Retinal thickness and the cell number in the ganglion cell layer were more retained in preconditioned animals after BCCAO compared to non-preconditioned group. These results suggest that preconditioning using sevoflurane could provide a new perspective in retinoprotective strategies.     

Calcineurin Aγ is a Functional Phosphatase That Modulates Synaptic Vesicle Endocytosis

Variation in PPP3CC, the gene that encodes the γ isoform of the calcineurin catalytic subunit, has been reported to be associated with schizophrenia. Because of its low expression level in most tissues, there has been little research devoted to the specific function of the calcineurin Aγ (CNAγ) versus the calcineurin Aα (CNAα) and calcineurin Aβ (CNAβ) catalytic isoforms. Consequently, we have a limited understanding of the role of altered CNAγ function in psychiatric disease. In this study, we demonstrate that CNAγ is present in the rodent and human brain and dephosphorylates a presynaptic substrate of calcineurin. Through a combination of immunocytochemistry and immuno-EM, we further show that CNAγ is localized to presynaptic terminals in hippocampal neurons. Critically, we demonstrate that RNAi-mediated knockdown of CNAγ leads to a disruption of synaptic vesicle cycling in cultured rat hippocampal neurons. These data indicate that CNAγ regulates a critical aspect of synaptic vesicle cycling and suggest that variation in PPP3CC may contribute to psychiatric disease by altering presynaptic function.     

Acetylarsenocholine: A Cholinergic Agonist

Abstract: The pharmacological properties of acetylarsenocholine, an arsenic analogue of acetylcholine, were investigated. Acetylarsenocholine behaved as a cholinergic ligand both in the central and peripheral nervous system. It bound to nicotinic receptors in rat medulla-pons with a K _D of 15 μ M and to muscarinic receptors in rat cerebral cortex with a K _D of 10 μ M . It behaved also as an agonist at presynaptic muscarinic receptors in guinea pig ileum myenteric plexus preparation. Arsenocholine is an alternative substrate for choline acetyltransferase and acetylarsenocholine is an alternative substrate for acetylcholinesterase.     

No overall benefit of predator exclosure cages for the endangered St. Helena Plover Charadrius sanctaehelenae

Predator exclosure cages are designed to increase the clutch survival of ground‐nesting birds. Predator exclosures provided for the endangered St. Helena Plover Charadrius sanctaehelenae, however, did not result in differences in clutch survival between protected and control nests and may have resulted in elevated adult mortality. Exclosures did not exclude all cats, the dominant nest predator, and it is likely that cats caused the adult mortalities observed close to the exclosures. A population model indicates that even if predator exclosures had excluded all cats, the benefits of increased clutch survival would have been more than negated by the estimated decrease in adult survival. The overall effect of predator exclosures needs to be clarified for other species, taking into consideration annual productivity and adult survival, to understand the circumstances in which predator exclosures are beneficial.