Glucocorticoids can induce PTSD-like memory impairments in mice

Posttraumatic stress disorder (PTSD) is characterized by a hypermnesia of the trauma and by a memory impairment that decreases the ability to restrict fear to the appropriate context. Infusion of glucocorticoids in the hippocampus after fear conditioning induces PTSD-like memory impairments and an altered pattern of neural activation in the hippocampal-amygdalar circuit. Mice become unable to identify the context as the correct predictor of the threat and show fear responses to a discrete cue not predicting the threat in normal conditions. These data demonstrate PTSD-like memory impairments in rodents and identify a potential pathophysiological mechanism of this condition.     

Brodifacoum is effective against Norway rats (Rattus norvegicus) in a tyrosine139cysteine focus of anticoagulant resistance in Westphalia,Germany

BACKGROUND: The tyrosine to cysteine amino acid substitution at location 139 of the vkorc1 protein (i.e. tyrosine139cysteine or Y139C) is the most widespread anticoagulant resistance mutation in Norway rats (Rattus norvegicus Berk.) in Europe. Field trials were conducted to determine the incidence of the Y139C mutation at two rat‐infested farms in Westphalia, Germany, and to estimate the practical efficacy against them of applications, using a pulsed baiting treatment regime, of a proprietary bait (Klerat^?) containing 0.005% brodifacoum. RESULTS: DNA analysis for the Y139C mutation showed that resistant rats were prevalent at the two farms, with an incidence of 80.0 and 78.6% respectively. Applications of brodifacoum bait achieved results of 99.2 and 100.0% control at the two farms, when measured by census baiting, although the treatment was somewhat prolonged at one site, possibly owing to the abundance of attractive alternative food. CONCLUSION: The study showed that 0.005% brodifacoum bait is fully effective against Norway rats possessing the Y139C mutation at the Münsterland focus and is likely to be so elsewhere in Europe where this mutation is found. The pulsed baiting regime reduced to relatively low levels the quantity of bait required to control these two substantial resistant Norway rat infestations. Previous studies had shown much larger quantities of bromadiolone and difenacoum baits used in largely ineffective treatments against Y139C resistant rats in the Münsterland. These results should be considered when making decisions about the use of anticoagulants against resistant Norway rats and their potential environmental impacts. Copyright © 2012 Society of Chemical Industry     

The crystal structure of human Argonaute2

Argonaute proteins form the functional core of the RNA-induced silencing complexes that mediate RNA silencing in eukaryotes. The 2.3 angstrom resolution crystal structure of human Argonaute2 (Ago2) reveals a bilobed molecule with a central cleft for binding guide and target RNAs. Nucleotides 2 to 6 of a heterogeneous mixture of guide RNAs are positioned in an A-form conformation for base pairing with target messenger RNAs. Between nucleotides 6 and 7, there is a kink that may function in microRNA target recognition or release of sliced RNA products. Tandem tryptophan-binding pockets in the PIWI domain define a likely interaction surface for recruitment of glycine-tryptophan-182 (GW182) or other tryptophan-rich cofactors. These results will enable structure-based approaches for harnessing the untapped therapeutic potential of RNA silencing in humans.     

Improving the sensitivity of the IBR-gE ELISA for testing IBR marker vaccinated cows from bulk milk

The low sensitivity of the IBR-gE ELISA compared to other diagnostic ELISA tests for IBR is a major disadvantage of IBR control programmes based on IBR marker vaccination. Therefore the IBR-gE ELISA is not generally recommended for testing pooled or bulk milk samples.The aim of this study was to determine the performance of a commercially available kit for concentrating and purifying antibodies in milk in order to improve the sensitivity of detecting IBR-gE antibody positive cows from pooled and bulk milk samples. A single IBR-gE positive cow is likely to remain undetected in a pool of 49 negative milk samples without concentration. By contrast, the bulk milk concentration procedure improved sensitivity from 5.4% to 75.7% in a positive herd. Milk samples with a high or moderate positive signal are more likely to be detected after pool milk concentration compared to weak positive samples. Whereas a follow up study involving a monthly testing of bulk milk samples from three marker vaccinated IBR-gE negative herds over a period of seven months yielded negative results each month, bulk milk from a herd containing <5% IBR-gE positive cows always detected positive after concentration. Although the milk concentration procedure had no impact on specificity, it significantly enhanced the sensitivity of the detection of IBR-gE positive milk in pooled and bulk milk samples. After further evaluation this procedure could allow a cost efficient and reliable method of monitoring IBR marker-vaccinated herds for IBR-gE antibodies.     

IMAGING FINDINGS IN 14 DOMESTIC FERRETS (MUSTELA PUTORIUS FURO) WITH LYMPHOMA

Lymphoma is the most common malignant neoplasia in domestic ferrets, Mustela putorius furo. However, imaging findings in ferrets with lymphoma have primarily been described in single case reports. The purpose of this retrospective study was to describe imaging findings in a group of ferrets with confirmed lymphoma. Medical records were searched between 2002 and 2012. A total of 14 ferrets were included. Radiographs (n = 12), ultrasound (n = 14), computed tomography (CT; n = 1), and magnetic resonance imaging (MRI; n = 1) images were available for review. Median age at the time of diagnosis was 5.2 years (range 3.25–7.6 years). Clinical signs were predominantly nonspecific (8/14). The time between the first imaging study and lymphoma diagnosis was 1 day or less in most ferrets (12). Imaging lesions were predominantly detected in the abdomen, and most frequently included intra‐abdominal lymphadenopathy (12/14), splenomegaly (8/14), and peritoneal effusion (11/14). Lymphadenopathy and mass lesions were typically hypoechoic on ultrasound. Mild peritoneal effusion was the only detected abnormality in two ferrets. Mild pleural effusion was the most common thoracic abnormality (3/12). Expansile lytic lesions were present in the vertebrae of two ferrets with T3‐L3 myelopathy and the femur in a ferret with lameness. Hyperattenuating, enhancing masses with secondary spinal cord compression were associated with vertebral lysis in CT images of one ferret. The MRI study in one ferret with myelopathy was inconclusive. Findings indicated that imaging characteristics of lymphoma in ferrets are similar to those previously reported in dogs, cats, and humans.